bcachefs: Fix btree_node_scan io_ref handling

This was completely fubar; it's now simplified a bit as well.
Note that for_each_online_member() takes and releases io_refs as it
iterates, so we need to release that if we break.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2025-03-01 16:14:28 -05:00
commit 2efa8397ca