firewire: fix compilation with gcc 3.4

drivers/firewire/fw-topology.c: In function `report_found_node':
drivers/firewire/fw-topology.c:345: error: `typeof' applied to a bit-field
drivers/firewire/fw-topology.c:345: error: `typeof' applied to a bit-field

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