https://patchwork.kernel.org/project/linux-nfs/patch/20220916214300.2820117-1-sam@gentoo.org/

From daf6aa9b659078aebd202fffff59bd9a0ab685ce Mon Sep 17 00:00:00 2001
From: Sam James <sam@gentoo.org>
Date: Fri, 16 Sep 2022 22:35:23 +0100
Subject: [PATCH] Fix more function prototypes

```
regex.c:545:43: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes]
struct trans_func *libnfsidmap_plugin_init()
                                          ^
                                           void
1 error generated.
```

See: 167f2336b06e1bcbf26f45f2ddc4a535fed4d393
Signed-off-by: Sam James <sam@gentoo.org>
--- a/support/nfsidmap/regex.c
+++ b/support/nfsidmap/regex.c
@@ -542,7 +542,7 @@ struct trans_func regex_trans = {
 	.gss_princ_to_grouplist	= regex_gss_princ_to_grouplist,
 };
 
-struct trans_func *libnfsidmap_plugin_init()
+struct trans_func *libnfsidmap_plugin_init(void)
 {
 	return (&regex_trans);
 }
--- a/utils/idmapd/idmapd.c
+++ b/utils/idmapd/idmapd.c
@@ -867,7 +867,7 @@ nfsdreopen_one(struct idmap_client *ic)
 }
 
 static void
-nfsdreopen()
+nfsdreopen(void)
 {
 	nfsdreopen_one(&nfsd_ic[IC_NAMEID]);
 	nfsdreopen_one(&nfsd_ic[IC_IDNAME]);