[NCCL] Log when barrier guesses device to use (#54991)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54991
Actual proposed fix is in
https://github.com/pytorch/pytorch/pull/53934, in the meantime, would be useful
to include this LOG when barrier does not know what devices to use, and suggest
the workaround of passing in device_ids into barrier().
ghstack-source-id: 126351889
Test Plan: CI
Reviewed By: SciPioneer
Differential Revision: D27444917
fbshipit-source-id: 0f269c5a7732e5be6e51adfca7ef70d04ffd71d3
