Fix autograd with buffers requiring grad in DataParallel (#13352)
Summary:
Causing a problem with spectral norm, although SN won't use that anymore after #13350 .
Pull Request resolved: https://github.com/pytorch/pytorch/pull/13352
Differential Revision: D14209562
Pulled By: ezyang
fbshipit-source-id: f5e3183e1e7050ac5a66d203de6f8cf56e775134
