[7.3] 80018d09e Constify (from flexelint)

[Dridi Boukelmoune]

commit 80018d09e59375e186e2b02498bdacca9b494eb0
Author: Nils Goroll <nils.goroll at uplex.de>
Date:   Mon Mar 20 11:58:51 2023 +0100

    Constify (from flexelint)

diff --git a/lib/libvarnish/vus.c b/lib/libvarnish/vus.c
index a110a1ec1..01187442f 100644
--- a/lib/libvarnish/vus.c
+++ b/lib/libvarnish/vus.c
@@ -196,7 +196,7 @@ socklen_t
 VUS_socklen(const struct sockaddr_un *uds)
 {
 	socklen_t sl;
-	char *p;
+	const char *p;
 	if (*uds->sun_path)
 		sl = sizeof(*uds);
 	else {