The previous version of the script would always print the default test
name even if user specified a different one.

BUG=angleproject:596

Change-Id: I43a07e81b49f69c7c372b46bd9494d6fe440b968
Reviewed-on: https://chromium-review.googlesource.com/319091Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Olli Etuaho <oetuaho@nvidia.com>