Fix warning messages
Fix warning messages

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