We wish to fail if we have >0 zero errors, not >1 errors (i.e. exactly
one error did not trigger a failure!)
This change also brings consistency to the pass & failure paths by
ensuring report_results exits in both cases, since report_results is
supposed to be the last thing run in a test file.
Change-Id: Id4721dffe13721e6c3cd71bca40c3395627e98bf