firewire: cdev: fix fw_cdev_event_bus_reset.bm_node_id

Fix an obscure ABI feature that is a bit of a hassle to implement.
However, somebody put it into the ABI, so let's fill in a sensible
value there.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/core-topology.c b/drivers/firewire/core-topology.c
index 56e908b..88d5133 100644
--- a/drivers/firewire/core-topology.c
+++ b/drivers/firewire/core-topology.c
@@ -552,6 +552,7 @@
 	smp_wmb();
 	card->generation = generation;
 	card->reset_jiffies = jiffies;
+	card->bm_node_id  = 0xffff;
 	card->bm_abdicate = bm_abdicate;
 	fw_schedule_bm_work(card, 0);