Fixed segfault when using compute_uv=false
Fixed segfault when using compute_uv=false

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