qeth: delete napi struct when removing a qeth device

qeth: delete napi struct when removing a qeth device

A qeth_card contains a napi_struct linked to the net_device during
device probing. This struct must be deleted when removing the qeth
device, otherwise Panic on oops can occur when qeth devices are
repeatedly removed and added.

Fixes: a1c3ed4c9ca ("qeth: NAPI support for l2 and l3 discipline")
Cc: [email protected] # v2.6.37+
Signed-off-by: Ursula Braun <[email protected]>
Tested-by: Alexander Klein <[email protected]>
Signed-off-by: David S. Miller <[email protected]>