Remove empty type_check_backward
Remove empty type_check_backward

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