[c10d] Fix monitored_barrier with wait_all_ranks (#58702)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58702
Off by one error when determining if some ranks failed or not with
`wait_all_ranks=True`. This wasn't caught by tests because the tests only
tested failure scenarios, not success scenarios with `wait_all_ranks=True`.
ghstack-source-id: 129559840
Test Plan: CI
Reviewed By: zhaojuanmao
Differential Revision: D28583235
fbshipit-source-id: a8f376efb13a3f36c788667acab86543c80aff59
