logit_backward: Port to structured (#60817)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/60817
Test Plan: Imported from OSS
Reviewed By: mruberry
Differential Revision: D29449376
Pulled By: ezyang
fbshipit-source-id: e6f793300488370f50a97db58f0400c557ee64e5
