virtio: fix typos of memory barriers

Note: this fixes a bug introduced recently in
7b21e34fd1c272e3a8c3846168f2f6287a4cd72b.

Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
1 file changed