teaming: fix vlan_features computing

__team_compute_features() uses netdev_increment_features() to
combine vlan_features of slaves into vlan_features of the team.
As netdev_increment_features() only adds most features and we
start with TEAM_VLAN_FEATURES, we can end up with features none
of the slaves provided.

Initialize vlan_features only with the flags which are both in
TEAM_VLAN_FEATURES and NETIF_F_ALL_FOR_ALL. Right now there is
no such feature so that we actually initialize vlan_features
with zero but stating it explicitely will make the code more
future proof.
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/team/team.c

@@ -968,7 +968,7 @@ static void team_port_disable(struct team *team,
 static void __team_compute_features(struct team *team)
 {
 	struct team_port *port;
-	u32 vlan_features = TEAM_VLAN_FEATURES;
+	u32 vlan_features = TEAM_VLAN_FEATURES & NETIF_F_ALL_FOR_ALL;
 	unsigned short max_hard_header_len = ETH_HLEN;
 	unsigned int flags, dst_release_flag = IFF_XMIT_DST_RELEASE;