bonding: remove bond_vlan_used()

We're using it currently to verify if we have vlans before getting the tag
from the skb we're about to send. It's useless because the vlan_get_tag()
verifies if the skb has the tag (and returns an error if not), and we can
receive tagged skbs only if we *already* have vlans.

Plus, the current RCUed implementation is kind of useless anyway - the we
can remove the last vlan in the moment we return from the function.

So remove the only usage of it and the whole function.

CC: Jay Vosburgh <fubar@us.ibm.com>
CC: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/bonding/bond_alb.c

@@ -694,10 +694,8 @@ static struct slave *rlb_choose_channel(struct sk_buff *skb, struct bonding *bon
 			client_info->ntt = 0;
 		}
 
-		if (bond_vlan_used(bond)) {
 		if (!vlan_get_tag(skb, &client_info->vlan_id))
 			client_info->tag = 1;
-		}
 
 		if (!client_info->assigned) {
 			u32 prev_tbl_head = bond_info->rx_hashtbl_used_head;

drivers/net/bonding/bonding.h

@@ -261,24 +261,6 @@ struct bonding {
 #endif /* CONFIG_DEBUG_FS */
 };
 
-/* if we hold rtnl_lock() - call vlan_uses_dev() */
-static inline bool bond_vlan_used(struct bonding *bond)
-{
-	struct net_device *upper;
-	struct list_head *iter;
-
-	rcu_read_lock();
-	netdev_for_each_upper_dev_rcu(bond->dev, upper, iter) {
-		if (upper->priv_flags & IFF_802_1Q_VLAN) {
-			rcu_read_unlock();
-			return true;
-		}
-	}
-	rcu_read_unlock();
-
-	return false;
-}
-
 #define bond_slave_get_rcu(dev) \
 	((struct slave *) rcu_dereference(dev->rx_handler_data))