Remove superfluous check (#23370)
Summary:
This check is not needed. Even if it were, the assignment is clobbered anyway.
Closes #23300.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23370
ghstack-source-id: 87157671
Differential Revision: D16485329
fbshipit-source-id: 8ccac79e81f5e0d0d20099d550411c161f58c233
