[PyTorch/d2go] fix optim _multi_tensor (#73215)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/73215
Fixing an issue in optimizers from _multi_tensor, for `sgd_mt` introduced in https://github.com/pytorch/pytorch/commit/2cb03e926f013493cb3986bb1c9446594b602385
Reviewed By: mikaylagawarecki
Differential Revision: D34389034
fbshipit-source-id: ede153d52dca15909c6c022853589707f18dc8d1
(cherry picked from commit cc8a58e58459265414cceb975697e5bf83de154d)
