fixed reference to unreachable stats.

Author: steenzout

tests/plugins/callback/idempotence.py

@@ -16,7 +16,7 @@ def playbook_on_stats(self, stats):
 
         if (u'%s' % VAR_IDEMPOTENCE) in self.playbook.extra_vars.keys() and self.playbook.extra_vars[VAR_IDEMPOTENCE]:
 
-            if len(stats.unreachable) > 0:
+            if len(stats.dark) > 0:
                 print ('idempotence test failed! unreachable=%s > 0') % stats.dark
                 sys.exit(os.EX_SOFTWARE)