Fix Gather::apply accessing moved tensors (#39733)
Summary:
Somehow this gets uncovered when I make changes in https://github.com/pytorch/pytorch/pull/39710
Pull Request resolved: https://github.com/pytorch/pytorch/pull/39733
Differential Revision: D21956034
Pulled By: albanD
fbshipit-source-id: e6d9097d67a4d0951ae6ccd2c5fb4cd54c536960
