sunrpc: mark all struct rpc_procinfo instances as const

struct rpc_procinfo contains function pointers, and marking it as
constant avoids it being able to be used as an attach vector for
code injections.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index fe4ec82..9d8166c 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -531,7 +531,7 @@ static int nsm_xdr_dec_stat(struct rpc_rqst *rqstp,
 #define SM_monres_sz	2
 #define SM_unmonres_sz	1
 
-static struct rpc_procinfo	nsm_procedures[] = {
+static const struct rpc_procinfo nsm_procedures[] = {
 [NSMPROC_MON] = {
 		.p_proc		= NSMPROC_MON,
 		.p_encode	= nsm_xdr_enc_mon,