Fix FreeUnusedBlocks
Fix FreeUnusedBlocks

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