test.c: Fix too sticky unit test failed status.

Rerunning a failed unit test after loading any required modules should
allow the test to report a pass status if it now passes.
........

Merged revisions 403782 from http://svn.asterisk.org/svn/asterisk/branches/12


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@403784 65c4cc65-6c06-0410-ace0-fbb531ad65f3