Don't include <unistd.h>. system.h already does that.

src/hostid.c

@@ -1,5 +1,5 @@
 /* print the hexadecimal identifier for the current host
-   Copyright (C) 1997, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+   Copyright (C) 1997, 1999, 2000, 2001, 2002, 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
@@ -20,9 +20,6 @@
 #include <config.h>
 #include <stdio.h>
 #include <sys/types.h>
-#if HAVE_UNISTD_H
-# include <unistd.h>
-#endif
 
 #include "system.h"
 #include "closeout.h"