[Bug]: return directly from running function (#413)

* fix bug of return directly from run function

* fix epoch based runner

* remove debug print

mmcv/runner/epoch_based_runner.py

@@ -118,7 +118,7 @@ class EpochBasedRunner(BaseRunner):
 
                 for _ in range(epochs):
                     if mode == 'train' and self.epoch >= max_epochs:
-                        return
+                        break
                     epoch_runner(data_loaders[i], **kwargs)
 
         time.sleep(1)  # wait for some hooks like loggers to finish

mmcv/runner/iter_based_runner.py

@@ -115,7 +115,7 @@ class IterBasedRunner(BaseRunner):
                 iter_runner = getattr(self, mode)
                 for _ in range(iters):
                     if mode == 'train' and self.iter >= max_iters:
-                        return
+                        break
                     iter_runner(iter_loaders[i], **kwargs)
 
         time.sleep(1)  # wait for some hooks like loggers to finish