bcachefs: Add missing READ_ONCE() for metadata replicas

If we race with the user changing the metadata_replicas setting, this
could cause us to get an incorrectly sized disk reservation.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2025-04-16 18:28:25 -04:00
commit 8dd3804bf4