Fix minor typo in comment (#42184)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/42184
Signed-off-by: Edward Z. Yang <ezyang@fb.com>
Test Plan: Imported from OSS
Reviewed By: albanD
Differential Revision: D22809375
Pulled By: ezyang
fbshipit-source-id: 322a4c2059b612a10c6257013bbf2fd207e75df7
