virtio_error: don't invoke status callbacks

Backends don't need to know what frontend requested a reset,
and notifying then from virtio_error is messy because
virtio_error itself might be invoked from backend.

Let's just set the status directly.

Cc: qemu-stable@nongnu.org
Reported-by: NIlya Maximets <i.maximets@samsung.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>

hw/virtio/virtio.c

@@ -2469,7 +2469,7 @@ void GCC_FMT_ATTR(2, 3) virtio_error(VirtIODevice *vdev, const char *fmt, ...)
     va_end(ap);
 
     if (virtio_vdev_has_feature(vdev, VIRTIO_F_VERSION_1)) {
-        virtio_set_status(vdev, vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET);
+        vdev->status = vdev->status | VIRTIO_CONFIG_S_NEEDS_RESET;
         virtio_notify_config(vdev);
     }