Fix lint/mypy violations (#70059)
Summary:
Introduced by https://github.com/pytorch/pytorch/pull/69194
Fixes #{issue number}
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70059
Reviewed By: suo, cccclai
Differential Revision: D33170748
Pulled By: malfet
fbshipit-source-id: a2e42f37d04c21a735f6474e42eb6670d2a0c3b9
