Update chainer/training/extensions/log_report.py
Update chainer/training/extensions/log_report.py

Co-Authored-By: crcrpar <5d40c5c70d3d1edb83028cb0acf367584fd843d9@gmail.com>
wkentaro/chainer,hvy/chainer,okuta/chainer,wkentaro/chainer,keisuke-umezawa/chainer,okuta/chainer,hvy/chainer,keisuke-umezawa/chainer,chainer/chainer,niboshi/chainer,wkentaro/chainer,okuta/chainer,chainer/chainer,keisuke-umezawa/chainer,hvy/chainer,hvy/chainer,tkerola/chainer,chainer/chainer,chainer/chainer,pfnet/chainer,keisuke-umezawa/chainer,niboshi/chainer,wkentaro/chainer,niboshi/chainer,niboshi/chainer,okuta/chainer