sys_util: clock: Make clippy clean
sys_util: clock: Make clippy clean

Signed-off-by: Dylan Reid <c791bfe44996c1eed9c7149a0c5f12a86d58eb85@chromium.org>
Change-Id: I321af88908e14af08886fdfe5191bde5335c247a
Reviewed-on: https://chromium-review.googlesource.com/1510432
Commit-Ready: ChromeOS CL Exonerator Bot <fa429e5907f00867f797423aea74327bb02c91b6@appspot.gserviceaccount.com>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Stephen Barber <7719587e4b5a49340661b214ec85602f3918d06f@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm