fix warning in row_conv_op.cu
fix warning in row_conv_op.cu

lcy-seso/Paddle,lcy-seso/Paddle,Canpio/Paddle,chengduoZH/Paddle,tensor-tang/Paddle,luotao1/Paddle,QiJune/Paddle,luotao1/Paddle,pkuyym/Paddle,tensor-tang/Paddle,reyoung/Paddle,tensor-tang/Paddle,Canpio/Paddle,putcn/Paddle,lcy-seso/Paddle,QiJune/Paddle,reyoung/Paddle,PaddlePaddle/Paddle,chengduoZH/Paddle,luotao1/Paddle,Canpio/Paddle,Canpio/Paddle,reyoung/Paddle,PaddlePaddle/Paddle,baidu/Paddle,PaddlePaddle/Paddle,chengduoZH/Paddle,putcn/Paddle,PaddlePaddle/Paddle,jacquesqiao/Paddle,jacquesqiao/Paddle,QiJune/Paddle,Canpio/Paddle,baidu/Paddle,Canpio/Paddle,chengduoZH/Paddle,putcn/Paddle,chengduoZH/Paddle,Canpio/Paddle,reyoung/Paddle,putcn/Paddle,pkuyym/Paddle,QiJune/Paddle,jacquesqiao/Paddle,QiJune/Paddle,jacquesqiao/Paddle,jacquesqiao/Paddle,luotao1/Paddle,putcn/Paddle,tensor-tang/Paddle,lcy-seso/Paddle,PaddlePaddle/Paddle,baidu/Paddle,pkuyym/Paddle,PaddlePaddle/Paddle,baidu/Paddle,pkuyym/Paddle,reyoung/Paddle,PaddlePaddle/Paddle,jacquesqiao/Paddle,reyoung/Paddle,QiJune/Paddle,putcn/Paddle,luotao1/Paddle,luotao1/Paddle,lcy-seso/Paddle,pkuyym/Paddle,lcy-seso/Paddle,baidu/Paddle,luotao1/Paddle,Canpio/Paddle,tensor-tang/Paddle,pkuyym/Paddle