Fix another logic bug for --shard-index in base test triggerer.

Bug: 926987
Change-Id: If17689c69a0c3f2ada5c40a844bea60376a96b61
Reviewed-on: https://chromium-review.googlesource.com/c/1480543
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#634299}
1 file changed