Remove cuda free mutex (#23040)
Summary:
Revision of https://github.com/pytorch/pytorch/issues/22173 to address CI failure after merging.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23040
Differential Revision: D16366872
Pulled By: mrshenli
fbshipit-source-id: 747b6ecf2dc195c25f82b8f732ae9ff52cd3a394
