autotest: Return true if no factor is blocking run_suite pre-check.

BUG=chromium:774124
TEST=Test on suite_scheduler golo proxy server.

Change-Id: I5bed8a17ee6e9b30a451f3f8a5076b13202a61bc
Reviewed-on: https://chromium-review.googlesource.com/716305
Commit-Queue: Xixuan Wu <xixuan@chromium.org>
Tested-by: Xixuan Wu <xixuan@chromium.org>
Trybot-Ready: Xixuan Wu <xixuan@chromium.org>
Reviewed-by: Dan Shi <dshi@google.com>
diff --git a/site_utils/run_suite.py b/site_utils/run_suite.py
index 36b84d5..71b9557 100755
--- a/site_utils/run_suite.py
+++ b/site_utils/run_suite.py
@@ -1959,6 +1959,8 @@
                      afe_job_id)
         return False
 
+    return True
+
 
 def _poke_buildbot_with_output(afe, job_id, job_timer):
     """Poke buildbot so it doesn't timeout from silence.