Fix for msgq tests on Python 3.2

The behavior of the unittest module was changed in the face of a
test exiting, so we need to use os._exit() instead of sys.exit()
to terminate.

src/bin/msgq/tests/msgq_test.py

@@ -132,7 +132,7 @@ class SendNonblock(unittest.TestCase):
             task()
             # If we got here, then everything worked well and in time
             # In that case, we terminate successfully
-            sys.exit(0)	# needs exit code
+            os._exit(0)	# needs exit code
         else:
             (pid, status) = os.waitpid(task_pid, 0)
             self.assertEqual(0, status,