In set_netdev(), the peers[i] is initialized
qemu_find_net_clients_except() when i is in
0 between 'queues' it can't be NULL.

Signed-off-by: Li Qiang <liq3ea@gmail.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <1541751214-17515-1-git-send-email-liq3ea@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>