sunrpc: Const-ify struct sv_serv_ops

Close an attack vector by moving the arrays of per-server methods to
read-only memory.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/lockd/svc.c b/fs/lockd/svc.c
index 726b6ce..b995bdc 100644
--- a/fs/lockd/svc.c
+++ b/fs/lockd/svc.c
@@ -396,7 +396,7 @@ static int lockd_start_svc(struct svc_serv *serv)
 	return error;
 }
 
-static struct svc_serv_ops lockd_sv_ops = {
+static const struct svc_serv_ops lockd_sv_ops = {
 	.svo_shutdown		= svc_rpcb_cleanup,
 	.svo_enqueue_xprt	= svc_xprt_do_enqueue,
 };