CRISv10 Ethernet declare mac fix

Declare mac using DECLARE_MAC_BUF for use when calling print_mac().

This fixes compile error where mac was undeclared.
Also, remove unused variable i.

Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Mikael Starvik <mikael.starvik@axis.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>