vsock/virtio: add a missing __le annotation

guest cid is read from config space, therefore it's in little endian
format and is treated as such, annotate it accordingly.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

net/vmw_vsock/virtio_transport.c

@@ -379,7 +379,7 @@ static void virtio_vsock_reset_sock(struct sock *sk)
 static void virtio_vsock_update_guest_cid(struct virtio_vsock *vsock)
 {
 	struct virtio_device *vdev = vsock->vdev;
-	u64 guest_cid;
+	__le64 guest_cid;
 
 	vdev->config->get(vdev, offsetof(struct virtio_vsock_config, guest_cid),
 			  &guest_cid, sizeof(guest_cid));