net/xen-netfront: only clean up queues if present
net/xen-netfront: only clean up queues if present

If you simply load and unload the module without starting the interfaces,
the queues are never created and you get a bad pointer dereference.

Signed-off-by: Chas Williams <921b14f935223b321d369dedbe14228440f895fd@gmail.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs