bsc_msc_ip: Verify that the sccp connection is present.

The SCCP might have been freed by the error case already
so we need to check this one for zero.

openbsc/src/bsc_msc_ip.c

@@ -88,6 +88,7 @@ void bss_sccp_free_data(struct bss_sccp_connection_data *data)
 {
 	bsc_del_timer(&data->T10);
 	bsc_del_timer(&data->sccp_it);
+	if (data->sccp)
 		bsc_free_queued(data->sccp);
 	bts_free_queued(data);
 	llist_del(&data->active_connections);