ieee1394: nodemgr: take it easy if bus_rescan_devices fails

This happens.  No need to log a BUG trace.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

drivers/ieee1394/nodemgr.c

@@ -1600,9 +1600,8 @@ static void nodemgr_node_probe(struct host_info *hi, int generation)
 	 * just removed.  */
 
 	if (generation == get_hpsb_generation(host))
-		WARN_ON(bus_rescan_devices(&ieee1394_bus_type));
-
-	return;
+		if (bus_rescan_devices(&ieee1394_bus_type))
+			HPSB_DEBUG("bus_rescan_devices had an error");
 }
 
 static int nodemgr_send_resume_packet(struct hpsb_host *host)