Fix Flake8 (#54540)
Summary:
https://github.com/pytorch/pytorch/issues/54339 broke Flake8. This PR fixes it.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54540
Test Plan:
```
flake8
```
Reviewed By: walterddr
Differential Revision: D27274171
Pulled By: samestep
fbshipit-source-id: 4b440d72b4b5615f45e6fcb25f7a4c0423add272
