net/mlx5: Get vport ACL namespace by vport index

The ingress and egress ACL root namespaces are created per vport and
stored into arrays. However, the vport number is not the same as the
index. Passing the array index, instead of vport number, to get the
correct ingress and egress acl namespace.

Fixes: 9b93ab98

 ("net/mlx5: Separate ingress/egress namespaces for each vport")
Signed-off-by: Jianbo Liu <jianbol@mellanox.com>
Reviewed-by: Oz Shlomo <ozsh@mellanox.com>
Reviewed-by: Eli Britstein <elibr@mellanox.com>
Reviewed-by: Roi Dayan <roid@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>