Fix overwriting bug in imagenet example
Fix overwriting bug in imagenet example

kashif/chainer,jfsantos/chainer,wkentaro/chainer,laysakura/chainer,sinhrks/chainer,AlpacaDB/chainer,nushio3/chainer,AlpacaDB/chainer,sinhrks/chainer,wkentaro/chainer,keisuke-umezawa/chainer,hvy/chainer,jnishi/chainer,t-abe/chainer,ttakamura/chainer,hvy/chainer,tkerola/chainer,benob/chainer,pfnet/chainer,bayerj/chainer,ytoyama/yans_chainer_hackathon,hvy/chainer,umitanuki/chainer,ktnyt/chainer,elviswf/chainer,benob/chainer,muupan/chainer,chainer/chainer,ktnyt/chainer,wkentaro/chainer,kikusu/chainer,keisuke-umezawa/chainer,kikusu/chainer,masia02/chainer,chainer/chainer,anaruse/chainer,tigerneil/chainer,jnishi/chainer,cupy/cupy,wavelets/chainer,aonotas/chainer,delta2323/chainer,niboshi/chainer,t-abe/chainer,kuwa32/chainer,wkentaro/chainer,chainer/chainer,cupy/cupy,chainer/chainer,jnishi/chainer,niboshi/chainer,woodshop/complex-chainer,niboshi/chainer,hidenori-t/chainer,minhpqn/chainer,1986ks/chainer,Kaisuke5/chainer,hvy/chainer,jnishi/chainer,okuta/chainer,ttakamura/chainer,ikasumi/chainer,cupy/cupy,yanweifu/chainer,truongdq/chainer,ysekky/chainer,sou81821/chainer,tscohen/chainer,okuta/chainer,kiyukuta/chainer,cemoody/chainer,cupy/cupy,woodshop/chainer,ktnyt/chainer,niboshi/chainer,ktnyt/chainer,muupan/chainer,nushio3/chainer,tereka114/chainer,rezoo/chainer,keisuke-umezawa/chainer,ronekko/chainer,truongdq/chainer,okuta/chainer,okuta/chainer,keisuke-umezawa/chainer