Update profiler_hook.py

mmengine/hooks/profiler_hook.py

@@ -233,8 +233,7 @@ def after_train_epoch(self, runner):
             self._export_chrome_trace(runner)
 
     def after_train_iter(self, runner, batch_idx, data_batch, outputs):
-        """Update the content according to the schedule, and determine if the
-        content is exported."""
+        """profiler will call `step` method if it is not closed."""
         if not self._closed:
             self.profiler.step()
         if runner.iter == self.profile_times - 1 and not self.by_epoch: