drivers/net/defxx.c: use %pMF to show MAC address

Use the %pMF kernel extension to display the MAC address.

The address will still be displayed in the FDDI Canonical format.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>