msg_socket: Remove redundant supertrait bound

We have:

    unsafe trait AlignedNew: Sized + DataInit {...}

    unsafe trait DataInit: Copy + Send + Sync {...}

    trait Copy: Clone {...}

    trait Clone: Sized {...}

Since Sized is already indirectly a supertrait of DataInit, including it
again as a supertrait of AlignedNew has no effect. This CL removes the
redundant Sized bound.

TEST=cargo check

Change-Id: I8ee2a9ee8892c95e6b0dd4bac1b662cd97441984
Reviewed-on: https://chromium-review.googlesource.com/1568077
Commit-Ready: David Tolnay <dtolnay@chromium.org>
Tested-by: David Tolnay <dtolnay@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>

msg_socket/src/msg_on_socket.rs

@@ -209,7 +209,7 @@ rawfd_impl!(UnixDatagram);
 
 // This trait is unsafe as it use uninitialized memory.
 // Please only implement it for primitive types.
-unsafe trait AlignedNew: Sized + DataInit {
+unsafe trait AlignedNew: DataInit {
     unsafe fn from_unaligned(buffer: &[u8]) -> Option<Self> {
         let mut value = std::mem::uninitialized::<Self>();
         let value_mem = value.as_mut_slice();