Fix cudnn 64bit indexing issue (#34407)
Summary:
Fix https://github.com/pytorch/pytorch/issues/33143
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34407
Differential Revision: D20325106
Pulled By: ngimel
fbshipit-source-id: 5aa52295f5491f189b7a8bea0987f28de0589d98
