virtio-bus: avoid breaking build when open DEBUG switch

Signed-off-by: NGonglei <arei.gonglei@huawei.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

hw/virtio/virtio-bus.c

@@ -58,7 +58,7 @@ void virtio_bus_reset(VirtioBusState *bus)
 {
     VirtIODevice *vdev = virtio_bus_get_device(bus);
 
-    DPRINTF("%s: reset device.\n", qbus->name);
+    DPRINTF("%s: reset device.\n", BUS(bus)->name);
     if (vdev != NULL) {
         virtio_reset(vdev);
     }