Fix forwarding of arguments into kernel function (#23412)
Summary:
They should be forwarded by their actual type, not their rvalue reference.
This looked like perfect forwarding but actually wasn't.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23412
ghstack-source-id: 87214575
Reviewed By: dzhulgakov
Differential Revision: D16507872
fbshipit-source-id: 2b20a37df83067dd53e917fe87407ad687bb147c
