fix opacus nn.functional import (#426)
Summary:
X-link: https://github.com/pytorch/opacus/pull/426
Pull Request resolved: https://github.com/pytorch/benchmark/pull/901
per title
Reviewed By: malfet, karthikprasad, anjali411
Differential Revision: D36172316
fbshipit-source-id: c9e665e57a69c8e87a6f5a0a902693ff90d99943
Author
Natalia Gimelshein
