Fix docstring
Fix docstring

chainer/chainer,ktnyt/chainer,jnishi/chainer,ktnyt/chainer,wkentaro/chainer,keisuke-umezawa/chainer,niboshi/chainer,wkentaro/chainer,keisuke-umezawa/chainer,wkentaro/chainer,chainer/chainer,keisuke-umezawa/chainer,hvy/chainer,niboshi/chainer,hvy/chainer,niboshi/chainer,okuta/chainer,ktnyt/chainer,okuta/chainer,wkentaro/chainer,hvy/chainer,rezoo/chainer,ktnyt/chainer,keisuke-umezawa/chainer,chainer/chainer,chainer/chainer,jnishi/chainer,jnishi/chainer,niboshi/chainer,okuta/chainer,jnishi/chainer,hvy/chainer,pfnet/chainer,tkerola/chainer,okuta/chainer