Created by: Steffy-zxf

1. fix code example of mul op ( drop paddle.fluid.data api append_batch_size param ) import paddle dataX = paddle.fluid.data(name="dataX", shape=[2, 5], dtype="float32") dataY = paddle.fluid.data(name="dataY", shape=[5, 3], dtype="float32")

   res = paddle.fluid.data(name="output", shape=[2, 3], dtype="float32") output = paddle.mul(dataX, dataY, x_num_col_dims = 1, y_num_col_dims = 1, out=res)