tests: Do not specify filename when runing gr_unittest

This fixes the following warning

DEPRECATED: Using filename with gr_unittest does no longer have any effect.

Change-Id: I7d6dbc32ff794ebf2bc116fa7437062e6780b85f
diff --git a/python/qa_message_printer.py b/python/qa_message_printer.py
index 21e6852..b1bf05e 100755
--- a/python/qa_message_printer.py
+++ b/python/qa_message_printer.py
@@ -162,5 +162,4 @@
         
         
 if __name__ == '__main__':
-    gr_unittest.run(qa_message_printer, "qa_message_printer.xml")
- 
+    gr_unittest.run(qa_message_printer)