For forwards compatibility we have to allow unknown key types, and only
run the checks that make sense against them.
Fix a missing guard on k.k->type being known.
Reported-by: syzbot+ae4dc916da3ce51f284f@syzkaller.appspotmail.com
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
        if (type >= BKEY_TYPE_NR)
                return 0;
 
-       bkey_fsck_err_on((type == BKEY_TYPE_btree ||
-                         (flags & BKEY_INVALID_COMMIT)) &&
+       bkey_fsck_err_on(k.k->type < KEY_TYPE_MAX &&
+                        (type == BKEY_TYPE_btree || (flags & BKEY_INVALID_COMMIT)) &&
                         !(bch2_key_types_allowed[type] & BIT_ULL(k.k->type)), c, err,
                         bkey_invalid_type_for_btree,
                         "invalid key type for btree %s (%s)",