sysctl: Fixes nsm_local_state bounds

Bound nsm_local_state sysctl writings between SYSCTL_ZERO
and SYSCTL_INT_MAX.

The proc_handler has thus been updated to proc_dointvec_minmax.

Signed-off-by: Nicolas Bouchinet <nicolas.bouchinet@ssi.gouv.fr>
[ cel: updated to handle zero - UINT_MAX instead ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

Author: nbouchinet-anssi

fs/lockd/svc.c

@@ -467,9 +467,10 @@ static const struct ctl_table nlm_sysctls[] = {
 	{
 		.procname	= "nsm_local_state",
 		.data		= &nsm_local_state,
-		.maxlen		= sizeof(int),
+		.maxlen		= sizeof(nsm_local_state),
 		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
+		.proc_handler	= proc_douintvec,
+		.extra1		= SYSCTL_ZERO,
 	},
 };