RunBuildScript: minor clean up

BUG=chromium:202477
TEST=`./cbuildbot/run_tests` passes

Change-Id: Ic84e66455c7affbf47b92687ad897b599923f7c0
Reviewed-on: https://chromium-review.googlesource.com/230010
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
1 file changed