Fix two overindent lint errors in test/common_nn.py. (#22287)
Summary:
This keeps causing lint tests to fail.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/22287
Differential Revision: D16024524
Pulled By: bddppq
fbshipit-source-id: a3e3780a55943283e9c854e94ac06ea4715e5319
