After receiving a PADT and the socket is closed, user space will no
longer drop the reference to the pppoe device.
This leads to errors like this:
[ 488.570000] unregister_netdevice: waiting for eth0.2 to become free. Usage count = 2
Fixes: 287f3a943fe ("pppoe: Use workqueue to die properly when a PADT is received")
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
665a6cd809