Fix Typing Error for Padding with asymmetric signatures (#24895)
Summary:
This PR resolves https://github.com/pytorch/pytorch/issues/24806
Pull Request resolved: https://github.com/pytorch/pytorch/pull/24895
Differential Revision: D16925208
Pulled By: ezyang
fbshipit-source-id: f4a374ca86e2e99faa30ca4b41c681e9976fe2de
