Spoofcheck can't be enabled if VF MAC is zero.
Vice versa, can't zero MAC if spoofcheck is on.

Fixes: 8f7ba3ca ('net/mlx4: Add set VF mac address support')
Signed-off-by: NEugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: NTariq Toukan <tariqt@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>