fix cpu test; test=develop

python/paddle/fluid/tests/unittests/test_lstm_cudnn_op.py

@@ -171,9 +171,14 @@ class TestCUDNNLstmOp(OpTest):
         }
 
     def test_output_with_place(self):
+        if not self.testcuda():
+            pass
         place = core.CUDAPlace(0)
         self.check_output_with_place(place, atol=1e-5)
 
+    def testcuda(self):
+        return core.is_compiled_with_cuda()
+
 
 if __name__ == '__main__':
     unittest.main()