tools/patman: Don't call a non-existent suite

With a newer pylint we get a warning that gitutil.RunTests does not
exist, so remove the line.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/tools/patman/test_checkpatch.py b/tools/patman/test_checkpatch.py
index 11d003b..3bf16fe 100644
--- a/tools/patman/test_checkpatch.py
+++ b/tools/patman/test_checkpatch.py
@@ -530,4 +530,3 @@
 
 if __name__ == "__main__":
     unittest.main()
-    gitutil.RunTests()