rust: fix some tricium warnings in 1.47.0 ebuild

BUG=None
TEST=sudo emerge virtual/rust

Change-Id: I3bb51c3128e332db1878fef5e937635082cbdeb6
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/2502969
Reviewed-by: Bob Haarman <inglorion@chromium.org>
Tested-by: Bob Haarman <inglorion@chromium.org>
Commit-Queue: Navil Perez <navil@google.com>
2 files changed