cleanup lint scripts a bit (#27805)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/27805
The expressions syntax for actions is pretty cool! Using it to clean up
some of my convoluted checks from before
Test Plan: Imported from OSS
Differential Revision: D17909353
Pulled By: suo
fbshipit-source-id: 8b9a85476ba19452f48c532a2daed830f074088a
