Fix docstring
Fix docstring

keisuke-umezawa/chainer,chainer/chainer,cupy/cupy,hvy/chainer,wkentaro/chainer,ktnyt/chainer,rezoo/chainer,okuta/chainer,tkerola/chainer,cupy/cupy,wkentaro/chainer,cupy/cupy,jnishi/chainer,okuta/chainer,pfnet/chainer,kikusu/chainer,keisuke-umezawa/chainer,AlpacaDB/chainer,jnishi/chainer,okuta/chainer,keisuke-umezawa/chainer,benob/chainer,hvy/chainer,cupy/cupy,jnishi/chainer,keisuke-umezawa/chainer,cemoody/chainer,kiyukuta/chainer,kikusu/chainer,jnishi/chainer,anaruse/chainer,AlpacaDB/chainer,wkentaro/chainer,benob/chainer,niboshi/chainer,niboshi/chainer,delta2323/chainer,niboshi/chainer,aonotas/chainer,chainer/chainer,chainer/chainer,ktnyt/chainer,ronekko/chainer,chainer/chainer,ysekky/chainer,niboshi/chainer,hvy/chainer,wkentaro/chainer,okuta/chainer,hvy/chainer,kashif/chainer,ktnyt/chainer,ktnyt/chainer