!3339 [AutoParallel]fix bug for autoparallel gpu

Merge pull request !3339 from lichen/fix_bug_for_autoparallel_gpu

mindspore/train/model.py

@@ -426,7 +426,7 @@ class Model:
 
             # for data sink dataset_helper only iter once, other wise iter epoch_size times.
             for inputs in dataset_helper:
-                if _need_to_full():
+                if _need_to_full() and context.get_context("device_target") == "GPU":
                     inputs = _to_full_tensor(inputs, self._device_number, self._global_rank)
                 list_callback.step_begin(run_context)
                 outputs = self._train_network(*inputs)