Don't mix up \0 and NULL, fatal with clang 15

graphics/vid/Makefile

@@ -1,7 +1,7 @@
 COMMENT=	get images from USB cameras using the OV511(+) chipsets
 
 DISTNAME=	vid-1.0.1
-REVISION=	5
+REVISION=	6
 CATEGORIES=	graphics
 
 HOMEPAGE=	http://ovtvid-bsd.sourceforge.net/

graphics/vid/patches/patch-vid_c

@@ -1,5 +1,6 @@
---- vid.c.orig	Mon May  8 06:59:03 2000
-+++ vid.c	Tue Apr 26 15:50:06 2016
+Index: vid.c
+--- vid.c.orig
++++ vid.c
 @@ -37,7 +37,7 @@
  
  #include <dev/usb/usb.h>
@@ -254,7 +255,7 @@
 +    /* there is a dot */
 +    plen = strlen(p);
 +    snprintf(isocdev, sizeof(isocdev), "%s", devname);
-+    isocdev[slen - plen] = NULL;
++    isocdev[slen - plen] = '\0';
 +    snprintf(isocdev, sizeof(isocdev), "%s.01", isocdev);
 +  }
 +