batman-adv: Clean up untagged vlan when destroying via rtnl-link

batman-adv: Clean up untagged vlan when destroying via rtnl-link

commit 420cb1b764f9169c5d2601b4af90e4a1702345ee upstream.

The untagged vlan object is only destroyed when the interface is removed
via the legacy sysfs interface. But it also has to be destroyed when the
standard rtnl-link interface is used.

Fixes: 5d2c05b21337 ("batman-adv: add per VLAN interface attribute framework")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Antonio Quartulli <a@unstable.cc>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: s/_put/_free_ref/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>