locks: add __acquires and __releases annotations to locks_start and locks_stop

...to make sparse happy.
Acked-by: NJ. Bruce Fields <bfields@fieldses.org>
Signed-off-by: NJeff Layton <jlayton@redhat.com>

fs/locks.c

@@ -2430,6 +2430,7 @@ static int locks_show(struct seq_file *f, void *v)
 }
 
 static void *locks_start(struct seq_file *f, loff_t *pos)
+	__acquires(&blocked_lock_lock)
 {
 	struct locks_iterator *iter = f->private;
 
@@ -2448,6 +2449,7 @@ static void *locks_next(struct seq_file *f, void *v, loff_t *pos)
 }
 
 static void locks_stop(struct seq_file *f, void *v)
+	__releases(&blocked_lock_lock)
 {
 	spin_unlock(&blocked_lock_lock);
 	lg_global_unlock(&file_lock_lglock);