checkpolicy: do not leak queue elements in queue_destroy()

Elements which are inserted into a queue_t object are either NULL (from
insert_separator()) or strings allocated with malloc() in insert_id().
They would be freed if there are still present in the queue when it is
destroyed. Otherwise the memory allocated for these elements would be
leaked.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>

checkpolicy/queue.c

@@ -113,6 +113,7 @@ void queue_destroy(queue_t q)
 
 	p = q->head;
 	while (p != NULL) {
+		free(p->element);
 		temp = p;
 		p = p->next;
 		free(temp);