fix UT

Author: HydrogenSulfate

source/tests/pd/model/test_deeppot.py

@@ -42,7 +42,7 @@ def setUp(self) -> None:
  trainer = get_trainer(deepcopy(self.config))
  trainer.run()
 
- with paddle.device("cpu"):
+ with paddle.device.device_guard("cpu"):
  input_dict, label_dict, _ = trainer.get_data(is_train=False)
  trainer.wrapper(**input_dict, label=label_dict, cur_lr=1.0)
  self.model = "model.pd"