net/mlx5e: Don't support encap rules with gbp option

Previously, encap rules with gbp option would be offloaded by mistake but
driver does not support gbp option offload.

To fix this issue, check if the encap rule has gbp option and don't
offload the rule

Fixes: d8f9dfae ("net: sched: allow flower to match vxlan options")
Signed-off-by: Gavin Li <gavinl@nvidia.com>
Reviewed-by: Maor Dickman <maord@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun_vxlan.c

@@ -88,6 +88,8 @@ static int mlx5e_gen_ip_tunnel_header_vxlan(char buf[],
 	struct udphdr *udp = (struct udphdr *)(buf);
 	struct vxlanhdr *vxh;
 
+	if (tun_key->tun_flags & TUNNEL_VXLAN_OPT)
+		return -EOPNOTSUPP;
 	vxh = (struct vxlanhdr *)((char *)udp + sizeof(struct udphdr));
 	*ip_proto = IPPROTO_UDP;