pytorch

21e9d114 - fix use-after-free bug

fix use-after-free bug Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/25965 Test Plan: Imported from OSS Differential Revision: D17300835 Pulled By: zdevito fbshipit-source-id: dd22d71687f03a5900aec4e36b795e1b13904eee