Include <stddef.h>.

(NULL): Don't define, since <stddef.h> does that.

lib/modechange.c

@@ -1,5 +1,7 @@
 /* modechange.c -- file mode manipulation
-   Copyright (C) 1989, 1990, 1997, 1998, 1999, 2001 Free Software Foundation, Inc.
+
+   Copyright (C) 1989, 1990, 1997, 1998, 1999, 2001, 2003 Free Software
+   Foundation, Inc.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -31,6 +33,7 @@
 #include "modechange.h"
 #include <sys/stat.h>
 #include "xstrtol.h"
+#include <stddef.h>
 
 #if STDC_HEADERS
 # include <stdlib.h>
@@ -38,10 +41,6 @@
 char *malloc ();
 #endif
 
-#ifndef NULL
-# define NULL 0
-#endif
-
 #if STAT_MACROS_BROKEN
 # undef S_ISDIR
 #endif