clang-format by line (#15657)
Summary:
This should further reduce noise by only clang-formatting the lines you actually touched in the precommit hook.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15657
Differential Revision: D15717337
Pulled By: suo
fbshipit-source-id: 57e65a679a8fdee5c3ff28e241c74ced9398eb0c
