team: Fix feature exposure when no ports are present

Small follow-up to align this to an equivalent behavior as the bond driver.
The change in 3625920 ("teaming: fix vlan_features computing") removed
the netdevice vlan_features when there is no team port attached, yet it
leaves the full set of enc_features intact.

Instead, leave the default features as pre 3625920, and recompute once
we do have ports attached. Also, similarly as in bonding case, call the
netdev_base_features() helper on the enc_features.

Fixes: 3625920 ("teaming: fix vlan_features computing")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20241213123657.401868-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: borkmann

drivers/net/team/team_core.c

@@ -998,9 +998,13 @@ static void __team_compute_features(struct team *team)
 	unsigned int dst_release_flag = IFF_XMIT_DST_RELEASE |
 					IFF_XMIT_DST_RELEASE_PERM;
 
+	rcu_read_lock();
+	if (list_empty(&team->port_list))
+		goto done;
+
 	vlan_features = netdev_base_features(vlan_features);
+	enc_features = netdev_base_features(enc_features);
 
-	rcu_read_lock();
 	list_for_each_entry_rcu(port, &team->port_list, list) {
 		vlan_features = netdev_increment_features(vlan_features,
 					port->dev->vlan_features,
@@ -1010,11 +1014,11 @@ static void __team_compute_features(struct team *team)
 						  port->dev->hw_enc_features,
 						  TEAM_ENC_FEATURES);
 
-
 		dst_release_flag &= port->dev->priv_flags;
 		if (port->dev->hard_header_len > max_hard_header_len)
 			max_hard_header_len = port->dev->hard_header_len;
 	}
+done:
 	rcu_read_unlock();
 
 	team->dev->vlan_features = vlan_features;