net/mlx5: fix VLAN flow action with wildcard VLAN item

net/mlx5: fix VLAN flow action with wildcard VLAN item

Previous patch added support of VLAN item without VLAN ID value,
i.e. using wildcard VLAN item, to match VLAN with any VLAN ID.
The implication on VLAN actions was not taken into consideration.
VLAN actions (e.g. push vlan) use the VLAN ID value in the VLAN item,
and expect it to be valid.

This patch updates function flow_dev_get_vlan_info_from_items() to
check the VLAN item contents before trying to use it.

Fixes: 92818d839e8e ("net/mlx5: fix match on empty VLAN item in DV mode")
Cc: stable@dpdk.org
Signed-off-by: Dekel Peled <dekelp@mellanox.com>
Acked-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>