Change virlet conformance logs grab behaviour

- Use fixture as usual

Change-Id: I821560beae671d3e4f9ec4cc5ef2b7710701f52a
diff --git a/tcp_tests/tests/system/test_virtlet_actions.py b/tcp_tests/tests/system/test_virtlet_actions.py
index 21f7454..e0e8011 100644
--- a/tcp_tests/tests/system/test_virtlet_actions.py
+++ b/tcp_tests/tests/system/test_virtlet_actions.py
@@ -92,7 +92,8 @@
     @pytest.mark.grab_versions
     @pytest.mark.grab_virtlet_results(name='virtlet_conformance.log')
     @pytest.mark.fail_snapshot
-    def test_virtlet_conformance(self, show_step, config, k8s_deployed):
+    def test_virtlet_conformance(self, show_step, config, k8s_deployed,
+                                 virtlet_logs):
         """Test run of virtlet conformance tests
 
         Scenario: