firewire: cdev: fix race of ioctl_send_request with bus reset

The bus reset handler concurrently frees client->device->node.  Use
device->node_id instead.  This is equivalent to device->node->node_id
while device->generation is current.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

diff --cc drivers/firewire/fw-cdev.c
Simple merge