drivers/net/82596.c: fix warning

drivers/net/82596.c: In function 'i596_open':
drivers/net/82596.c:1044: warning: label 'err_irq_dev' defined but not used

Caused by "82596: free resources on error"

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>