net/mlx5: fix VLAN VID action validation

net/mlx5: fix VLAN VID action validation

Validation function of 'set VLAN VID' action checks twice for existing
same action in flow rule.

This patch updates the validation function logic, to check the same
restrictions more efficiently.

Fixes: 5f163d520cff ("net/mlx5: support modify VLAN ID on existing VLAN header")
Fixes: b8c0372bc5ac ("net/mlx5: fix set VLAN ID/PCP in new header")
Cc: stable@dpdk.org
Signed-off-by: Dekel Peled <dekelp@mellanox.com>
Acked-by: Ori Kam <orika@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>