Fix symbolic derivative of hardswish (#59405)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/59405
Test Plan: Imported from OSS
Reviewed By: ngimel
Differential Revision: D28879698
Pulled By: bertmaher
fbshipit-source-id: 2f2d9836bf592b18ed9a19aab4f5967e653b5898
