Fix autopep8 error
Fix autopep8 error

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