parallel exec order bug fix

mindspore/nn/wrap/cell_wrapper.py

@@ -352,6 +352,7 @@ class TrainOneStepCell(Cell):
         weights = self.weights
         loss = self.network(*inputs)
         sens = P.Fill()(P.DType()(loss), P.Shape()(loss), self.sens)
+        sens = F.depend(sens, loss)
         grads = self.grad(self.network, weights)(*inputs, sens)
         grads = self.grad_reducer(grads)
         loss = F.depend(loss, self.optimizer(grads))