[moblab] Fix issue detecting if running on moblab

BUG=chromium:972478
TEST=local moblab testing

Change-Id: I85683ab533ee0e07628f542f76c0897f78cacecb
Reviewed-on: https://chromium-review.googlesource.com/1651576
Commit-Ready: Keith Haddow <haddowk@chromium.org>
Tested-by: Keith Haddow <haddowk@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Keith Haddow <haddowk@chromium.org>
1 file changed