Update doc to reflect current behavior (#46937)
Summary:
This behavior was changed by side effect by https://github.com/pytorch/pytorch/pull/41984
Update the doc to reflect the actual behavior of the function.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/46937
Reviewed By: mruberry
Differential Revision: D24682750
Pulled By: albanD
fbshipit-source-id: 89b94b61f54dbcfc6a6988d7e7d361bd24ee4964
