bcachefs: Add missing key type checks to check_snapshot_exists()

For now we only have one key type in these btrees, but forward
compatibility means we do have to check.

Reported-by: syzbot+b4cb4a6988aced0cec4b@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Kent Overstreet 2025-06-19 14:32:57 -04:00
commit b2e2bed119