UBUNTU: (pre-upstream) FEC: Fix kernel panic in fec_set_mac_address.

BugLink: http://bugs.launchpad.net/bugs/575558

Fix memory corruption that sometimes result in kernel panic.

Signed-off-by: Mattias Walström <mattias@vmlinux.org>
Signed-off-by: Bryan Wu <bryan.wu@canonical.com>
Acked-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Colin King <colin.king@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>