net: ndo_bridge_setlink: Add extack

Drivers may not be able to implement a VLAN addition or reconfiguration.
In those cases it's desirable to explain to the user that it was
rejected (and why).

To that end, add extack argument to ndo_bridge_setlink. Adapt all users
to that change.

Following patches will use the new argument in the bridge driver.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -9618,7 +9618,7 @@ static int bnxt_bridge_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 }
 
 static int bnxt_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
-			       u16 flags)
+			       u16 flags, struct netlink_ext_ack *extack)
 {
 	struct bnxt *bp = netdev_priv(dev);
 	struct nlattr *attr, *br_spec;