restricted trace tests: Fix script. This script was not parsing the trace list properly and was running no tests. Bug: angleproject:5811 Change-Id: I925bc16ac476823ca2f850d4a9e208b9bb5deb62 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2810805 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>