Variable not defined when running --lowprofile flag and reshape to batch_size issue

Hello,

I was experimenting with the --lowprofile flag but an error is thrown saying 'n_images' from line 226 of fid.py is not defined. Likely a typo since the author probably meant to reference n_imgs.

Additionally, line 234 pred_arr[start:end] = pred.reshape(batch_size,-1) will crash if the number of images is not divisible by batch_size. Which is the case with 2048 images and the default batch_size of 50.