wa: Rename update_results reference to update_output

To be consistant with the rename of output_processors, old references
to `update_results` have now been changed to `update_output`.

wa/workloads/rt_app/__init__.py

@@ -176,7 +176,7 @@ class RtApp(Workload):
                                          timeout=self.timeout,
                                          as_root=True)
 
-    def update_result(self, context):
+    def update_output(self, context):
         self._pull_rt_app_logs(context)
         context.result.classifiers.update(dict(
             duration=self.duration,