Currently the spapr-vlan device does not supply a cleanup call for its
NetClientInfo structure.  With current qemu versions, that leads to a SEGV
on exit, when net_cleanup() attempts to call the cleanup handlers on all
net clients.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Signed-off-by: NAlexander Graf <agraf@suse.de>