Fix docstring for nn.Hardshrink (#71012)
Summary:
Fixes nn.Hardshrkink's docstring problem reported at https://github.com/pytorch/pytorch/issues/70498.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/71012
Reviewed By: dagitses
Differential Revision: D33482333
Pulled By: jbschlosser
fbshipit-source-id: 00eea76299676fc97c5cc31421af9c73665bfcf4
