bcachefs: Add a cond_resched() call to journal_keys_sort()

We're just doing cpu work here and it could take awhile, a
cond_resched() is definitely needed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/recovery.c

@@ -543,6 +543,8 @@ static int journal_keys_sort(struct bch_fs *c)
 		if (!i || i->ignore)
 			continue;
 
+		cond_resched();
+
 		for_each_jset_key(k, entry, &i->j) {
 			if (keys->nr == keys->size) {
 				__journal_keys_sort(keys);