fix nccl dist train bug
fix nccl dist train bug

tensor-tang/Paddle,tensor-tang/Paddle,PaddlePaddle/Paddle,PaddlePaddle/Paddle,reyoung/Paddle,chengduoZH/Paddle,reyoung/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,PaddlePaddle/Paddle,tensor-tang/Paddle,luotao1/Paddle,jacquesqiao/Paddle,jacquesqiao/Paddle,PaddlePaddle/Paddle,chengduoZH/Paddle,jacquesqiao/Paddle,reyoung/Paddle,QiJune/Paddle,jacquesqiao/Paddle,jacquesqiao/Paddle,luotao1/Paddle,baidu/Paddle,reyoung/Paddle,QiJune/Paddle,luotao1/Paddle,baidu/Paddle,baidu/Paddle,luotao1/Paddle,jacquesqiao/Paddle,baidu/Paddle,baidu/Paddle,tensor-tang/Paddle,QiJune/Paddle,chengduoZH/Paddle,luotao1/Paddle,tensor-tang/Paddle,QiJune/Paddle,QiJune/Paddle,PaddlePaddle/Paddle,reyoung/Paddle,chengduoZH/Paddle,chengduoZH/Paddle,luotao1/Paddle,reyoung/Paddle,QiJune/Paddle,PaddlePaddle/Paddle