net/mlx5e: Remove incorrect addition of action fwd flag

A user is expected to explicit request a fwd or drop action.
It is not correct to implicit add a fwd action for the user,
when modify header action flag exists.

Signed-off-by: Roi Dayan <roid@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>