mlx4_en: clear all eth statistics when port goes up

Bug fix: Not all stats fields were cleared.

Signed-off-by: Eugenia Emantayev <eugenia@mellanox.co.il>
Reviewed-by: Yevgeny Petriln <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>