Fix some of the wrong comments in im2col.h file.
Fix some of the wrong comments in im2col.h file.

lispc/Paddle,luotao1/Paddle,putcn/Paddle,putcn/Paddle,jacquesqiao/Paddle,pengli09/Paddle,QiJune/Paddle,yu239/Paddle,baidu/Paddle,lispc/Paddle,pkuyym/Paddle,hedaoyuan/Paddle,reyoung/Paddle,yu239/Paddle,Canpio/Paddle,hedaoyuan/Paddle,lispc/Paddle,reyoung/Paddle,chengduoZH/Paddle,jacquesqiao/Paddle,QiJune/Paddle,lcy-seso/Paddle,QiJune/Paddle,hedaoyuan/Paddle,putcn/Paddle,hedaoyuan/Paddle,PaddlePaddle/Paddle,yu239/Paddle,lispc/Paddle,chengduoZH/Paddle,Canpio/Paddle,chengduoZH/Paddle,putcn/Paddle,QiJune/Paddle,baidu/Paddle,hedaoyuan/Paddle,lcy-seso/Paddle,luotao1/Paddle,PaddlePaddle/Paddle,pengli09/Paddle,reyoung/Paddle,luotao1/Paddle,pengli09/Paddle,reyoung/Paddle,jacquesqiao/Paddle,tensor-tang/Paddle,luotao1/Paddle,Canpio/Paddle,luotao1/Paddle,pkuyym/Paddle,hedaoyuan/Paddle,pkuyym/Paddle,pkuyym/Paddle,pengli09/Paddle,chengduoZH/Paddle,Canpio/Paddle,reyoung/Paddle,PaddlePaddle/Paddle,putcn/Paddle,lcy-seso/Paddle,lcy-seso/Paddle,tensor-tang/Paddle,PaddlePaddle/Paddle,yu239/Paddle,PaddlePaddle/Paddle,lispc/Paddle,baidu/Paddle,hedaoyuan/Paddle,luotao1/Paddle,pengli09/Paddle,PaddlePaddle/Paddle,putcn/Paddle,Canpio/Paddle,pkuyym/Paddle,QiJune/Paddle,yu239/Paddle,jacquesqiao/Paddle,lispc/Paddle,reyoung/Paddle,Canpio/Paddle,chengduoZH/Paddle,pengli09/Paddle,QiJune/Paddle,pengli09/Paddle,Canpio/Paddle,yu239/Paddle,lcy-seso/Paddle,jacquesqiao/Paddle,Canpio/Paddle,tensor-tang/Paddle,tensor-tang/Paddle,luotao1/Paddle,tensor-tang/Paddle,jacquesqiao/Paddle,pkuyym/Paddle,pengli09/Paddle,lispc/Paddle,lcy-seso/Paddle,hedaoyuan/Paddle,baidu/Paddle,yu239/Paddle,lispc/Paddle,yu239/Paddle,baidu/Paddle,PaddlePaddle/Paddle