net: add netlink_ext_ack argument to rtnl_link_ops.validate

Add support for extended error reporting.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index ae49f4b..3d4c245 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1580,7 +1580,8 @@ static void tun_setup(struct net_device *dev)
 /* Trivial set of netlink ops to allow deleting tun or tap
  * device with netlink.
  */
-static int tun_validate(struct nlattr *tb[], struct nlattr *data[])
+static int tun_validate(struct nlattr *tb[], struct nlattr *data[],
+			struct netlink_ext_ack *extack)
 {
 	return -EINVAL;
 }