update test_expand_v2_op_npu.py

Author: WorgenZhang

python/paddle/fluid/tests/unittests/npu/test_expand_v2_op_npu.py

@@ -132,9 +132,6 @@ def test_check_output(self):
         self.check_output_with_place(self.place)
 
     def test_check_grad(self):
-        if self.dtype == np.float16:
-            return
-
         self.check_grad_with_place(self.place, ['X'], 'Out')