allow dead code for usb modules

This will remove warning messages for dead code.

TEST=run crosvm locally
BUG=chromium:831850
CQ-DEPEND=CL:1510814
Change-Id: Ia5c8768647737e3091e1a0b5e435d3c25bbbe383
Reviewed-on: https://chromium-review.googlesource.com/1510815
Commit-Ready: Jingkui Wang <jkwang@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Zach Reizner <zachr@chromium.org>
Reviewed-by: Jingkui Wang <jkwang@google.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/devices/src/register_space/register.rs b/devices/src/register_space/register.rs
index abe9bb6..2cc5b30 100644
--- a/devices/src/register_space/register.rs
+++ b/devices/src/register_space/register.rs
@@ -4,7 +4,7 @@
 
 use std;
 use std::boxed::Box;
-use std::cmp::{max, min, Ord, Ordering, PartialEq, PartialOrd};
+use std::cmp::{max, min, Ord, Ordering, PartialOrd};
 use std::mem::size_of;
 use std::sync::{Arc, MutexGuard};
 use sync::Mutex;