Revert "virtio-blk: don't let virtio core to validate used length"

This reverts commit a40392ed.

Attempts to validate length in the core did not work out.
We'll drop them, so revert the dependent changes in drivers.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

drivers/block/virtio_blk.c

@@ -1049,7 +1049,6 @@ static struct virtio_driver virtio_blk = {
 	.feature_table_size		= ARRAY_SIZE(features),
 	.feature_table_legacy		= features_legacy,
 	.feature_table_size_legacy	= ARRAY_SIZE(features_legacy),
-	.suppress_used_validation	= true,
 	.driver.name			= KBUILD_MODNAME,
 	.driver.owner			= THIS_MODULE,
 	.id_table			= id_table,