Replace -f with -x for pytest tests. (#46967)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/46967
Tests under `tests/distributed/_pipeline/sync` use pytest and
specifying the `-f` option for such tests as follows: `python test/run_test.py
-i distributed/_pipeline/sync/skip/test_api -- -f` doesn't work.
The equivalent option for pytest is `-x`. To resolve this issue, I've updated
`run_test.py` to replace `-f` with `-x` for pytest tests.
More details in https://github.com/pytorch/pytorch/issues/46782
#Closes: https://github.com/pytorch/pytorch/issues/46782
ghstack-source-id: 115440558
Test Plan:
1) waitforbuildbot
2) `python test/run_test.py -i distributed/_pipeline/sync/skip/test_api -- -f`
Reviewed By: malfet
Differential Revision: D24584556
fbshipit-source-id: bd87f5b4953504e5659fe72fc8615e126e5490ff
