Fixes lint error in py3 (#21883)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21883
ghimport-source-id: c4330d71033929178ef10f2a0fcd8b0b2b468cb5
Test Plan: Imported from OSS
Differential Revision: D15866746
Pulled By: bwasti
fbshipit-source-id: c3d23f3396a95d5b1d689a07662e82e48cb3ab7a
