Fix error handling when serializing uninitialized parameters
Fix error handling when serializing uninitialized parameters

rezoo/chainer,keisuke-umezawa/chainer,ktnyt/chainer,tkerola/chainer,niboshi/chainer,cupy/cupy,jnishi/chainer,keisuke-umezawa/chainer,kiyukuta/chainer,keisuke-umezawa/chainer,wkentaro/chainer,hvy/chainer,chainer/chainer,jnishi/chainer,chainer/chainer,jnishi/chainer,keisuke-umezawa/chainer,ktnyt/chainer,cupy/cupy,hvy/chainer,wkentaro/chainer,okuta/chainer,cupy/cupy,ysekky/chainer,wkentaro/chainer,jnishi/chainer,hvy/chainer,aonotas/chainer,hvy/chainer,delta2323/chainer,ktnyt/chainer,okuta/chainer,okuta/chainer,kashif/chainer,anaruse/chainer,ktnyt/chainer,niboshi/chainer,chainer/chainer,niboshi/chainer,wkentaro/chainer,okuta/chainer,chainer/chainer,niboshi/chainer,cupy/cupy,pfnet/chainer,ronekko/chainer