virtio_input: Constify id_table

id_table is not modified, so make it const to allow the compiler to put
it in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20200911203509.26505-3-rikard.falkeborn@gmail.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>

drivers/virtio/virtio_input.c

@@ -363,7 +363,7 @@ static int virtinput_restore(struct virtio_device *vdev)
 static unsigned int features[] = {
 	/* none */
 };
-static struct virtio_device_id id_table[] = {
+static const struct virtio_device_id id_table[] = {
 	{ VIRTIO_ID_INPUT, VIRTIO_DEV_ANY_ID },
 	{ 0 },
 };