Fix nullptr when doing nested profileing
Fix nullptr when doing nested profileing

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