Fix inexistent parameter in document (#24335)
Summary:
There is no `out` argument to `argsort` according to the source code.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/24335
Differential Revision: D16829134
Pulled By: vincentqb
fbshipit-source-id: 8f91154984cd4a753ba1d6105fb8a9bfa0da22b3
