removed redundant reduce func
removed redundant reduce func

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