Fix loss finding on GPU
Fix loss finding on GPU

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