Remove unused variable
Remove unused variable

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