usb: Simplify imports from usb_util

The devices crate imports things from usb_util which is a separate
crate. Importing from a crate normally looks like:

    use name_of_crate::path::to::ThingToImport;

In the case it would be e.g.:

    use usb_util::hotplug::UsbHotplugHandler;

Importing these things through crate::usb::usb_util is unnecessary.

TEST=cargo check

Change-Id: I70554639a71b2423c1e13a30361d5f9d92e9d9a9
Reviewed-on: https://chromium-review.googlesource.com/1565725
Commit-Ready: David Tolnay <dtolnay@chromium.org>
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Tested-by: David Tolnay <dtolnay@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jingkui Wang <jkwang@google.com>

devices/src/usb/host_backend/context.rs

@@ -3,14 +3,14 @@
 // found in the LICENSE file.
 
 use super::error::*;
-use crate::usb::usb_util::hotplug::UsbHotplugHandler;
-use crate::usb::usb_util::libusb_context::{LibUsbContext, LibUsbPollfdChangeHandler};
-use crate::usb::usb_util::libusb_device::LibUsbDevice;
 use crate::utils::{EventHandler, EventLoop};
 use std::os::raw::c_short;
 use std::os::unix::io::RawFd;
 use std::sync::{Arc, Weak};
 use sys_util::WatchingEvents;
+use usb_util::hotplug::UsbHotplugHandler;
+use usb_util::libusb_context::{LibUsbContext, LibUsbPollfdChangeHandler};
+use usb_util::libusb_device::LibUsbDevice;
 use vm_control::MaybeOwnedFd;
 
 /// Context wraps libusb context with libusb event handling.

devices/src/usb/host_backend/error.rs

@@ -2,12 +2,12 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-use crate::usb::usb_util::error::Error as UsbUtilError;
 use crate::usb::xhci::scatter_gather_buffer::Error as BufferError;
 use crate::usb::xhci::xhci_transfer::Error as XhciTransferError;
 use crate::utils::Error as UtilsError;
 use msg_socket::MsgError;
 use std::fmt::{self, Display};
+use usb_util::error::Error as UsbUtilError;
 
 #[derive(Debug)]
 pub enum Error {

devices/src/usb/host_backend/host_device.rs

@@ -9,22 +9,22 @@ use sync::Mutex;
 use super::error::*;
 use super::usb_endpoint::UsbEndpoint;
 use super::utils::{submit_transfer, update_transfer_state};
-use crate::usb::usb_util::device_handle::DeviceHandle;
-use crate::usb::usb_util::error::Error as LibUsbError;
-use crate::usb::usb_util::libusb_device::LibUsbDevice;
-use crate::usb::usb_util::types::{
-    ControlRequestDataPhaseTransferDirection, ControlRequestRecipient, ControlRequestType,
-    StandardControlRequest, UsbRequestSetup,
-};
-use crate::usb::usb_util::usb_transfer::{
-    control_transfer, ControlTransferBuffer, TransferStatus, UsbTransfer,
-};
 use crate::usb::xhci::scatter_gather_buffer::ScatterGatherBuffer;
 use crate::usb::xhci::xhci_backend_device::{BackendType, UsbDeviceAddress, XhciBackendDevice};
 use crate::usb::xhci::xhci_transfer::{XhciTransfer, XhciTransferState, XhciTransferType};
 use crate::utils::AsyncJobQueue;
 use crate::utils::FailHandle;
 use std::collections::HashMap;
+use usb_util::device_handle::DeviceHandle;
+use usb_util::error::Error as LibUsbError;
+use usb_util::libusb_device::LibUsbDevice;
+use usb_util::types::{
+    ControlRequestDataPhaseTransferDirection, ControlRequestRecipient, ControlRequestType,
+    StandardControlRequest, UsbRequestSetup,
+};
+use usb_util::usb_transfer::{
+    control_transfer, ControlTransferBuffer, TransferStatus, UsbTransfer,
+};
 
 #[derive(PartialEq)]
 pub enum ControlEndpointState {

devices/src/usb/host_backend/hotplug.rs

@@ -4,9 +4,9 @@
 
 use std::sync::Arc;
 
-use crate::usb::usb_util::hotplug::{HotplugEvent, UsbHotplugHandler};
-use crate::usb::usb_util::libusb_device::LibUsbDevice;
 use crate::usb::xhci::usb_hub::UsbHub;
+use usb_util::hotplug::{HotplugEvent, UsbHotplugHandler};
+use usb_util::libusb_device::LibUsbDevice;
 
 pub struct HotplugHandler {
     hub: Arc<UsbHub>,

devices/src/usb/host_backend/usb_endpoint.rs

@@ -8,17 +8,17 @@ use sync::Mutex;
 
 use super::error::*;
 use super::utils::{submit_transfer, update_transfer_state};
-use crate::usb::usb_util::device_handle::DeviceHandle;
-use crate::usb::usb_util::types::{EndpointDirection, EndpointType, ENDPOINT_DIRECTION_OFFSET};
-use crate::usb::usb_util::usb_transfer::{
-    bulk_transfer, interrupt_transfer, BulkTransferBuffer, TransferStatus, UsbTransfer,
-};
 use crate::usb::xhci::scatter_gather_buffer::ScatterGatherBuffer;
 use crate::usb::xhci::xhci_transfer::{
     TransferDirection, XhciTransfer, XhciTransferState, XhciTransferType,
 };
 use crate::utils::AsyncJobQueue;
 use crate::utils::FailHandle;
+use usb_util::device_handle::DeviceHandle;
+use usb_util::types::{EndpointDirection, EndpointType, ENDPOINT_DIRECTION_OFFSET};
+use usb_util::usb_transfer::{
+    bulk_transfer, interrupt_transfer, BulkTransferBuffer, TransferStatus, UsbTransfer,
+};
 
 /// Isochronous, Bulk or Interrupt endpoint.
 pub struct UsbEndpoint {

devices/src/usb/host_backend/utils.rs

@@ -7,11 +7,11 @@ use std::sync::Arc;
 use sync::Mutex;
 
 use super::error::*;
-use crate::usb::usb_util::device_handle::DeviceHandle;
-use crate::usb::usb_util::usb_transfer::{TransferStatus, UsbTransfer, UsbTransferBuffer};
 use crate::usb::xhci::xhci_transfer::{XhciTransfer, XhciTransferState};
 use crate::utils::AsyncJobQueue;
 use crate::utils::FailHandle;
+use usb_util::device_handle::DeviceHandle;
+use usb_util::usb_transfer::{TransferStatus, UsbTransfer, UsbTransferBuffer};
 
 /// Helper function to update xhci_transfer state.
 pub fn update_transfer_state<T: UsbTransferBuffer>(

devices/src/usb/xhci/xhci_transfer.rs

@@ -10,14 +10,14 @@ use super::xhci_abi::{
     TrbCompletionCode, TrbType,
 };
 use super::xhci_regs::MAX_INTERRUPTER;
-use crate::usb::usb_util::types::UsbRequestSetup;
-use crate::usb::usb_util::usb_transfer::TransferStatus;
 use std::cmp::min;
 use std::fmt::{self, Display};
 use std::mem;
 use std::sync::{Arc, Weak};
 use sync::Mutex;
 use sys_util::{Error as SysError, EventFd, GuestMemory};
+use usb_util::types::UsbRequestSetup;
+use usb_util::usb_transfer::TransferStatus;
 
 #[derive(Debug)]
 pub enum Error {