ovn-northd: Fix memory leak in free_chassis_queueid().

Found by inspection.

Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Numan Siddique <nusiddiq@redhat.com>

ovn/northd/ovn-northd.c

@@ -375,6 +375,7 @@ free_chassis_queueid(struct hmap *set, struct sbrec_chassis *chassis,
         if (uuid_equals(&chassis->header_.uuid, &node->chassis_uuid)
             && node->queue_id == queue_id) {
             hmap_remove(set, &node->key_node);
+            free(node);
             break;
         }
     }