fix clang errors
fix clang errors

chainer/chainer,hvy/chainer,chainer/chainer,wkentaro/chainer,niboshi/chainer,chainer/chainer,hvy/chainer,niboshi/chainer,hvy/chainer,hvy/chainer,niboshi/chainer,niboshi/chainer,wkentaro/chainer,wkentaro/chainer,wkentaro/chainer,pfnet/chainer,chainer/chainer