firewire: net: remove set but not used variable 'guid'

Fixes gcc '-Wunused-but-set-variable' warning:

drivers/firewire/net.c:488:9: warning:
 variable ‘guid’ set but not used [-Wunused-but-set-variable]

It is not used anymore after commit 6752c8db8e0c ("firewire net, ipv4
arp: Extend hardware address and remove driver-level packet inspection.")

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
1 file changed