sys_errlist and strerror are const.

src/libraries/libansi/strerror.c

 /*
- * $Id: strerror.c,v 0.6 1992/02/26 18:46:01 ceder Exp $
+ * $Id: strerror.c,v 0.7 1992/06/11 18:46:07 ceder Exp $
  * Copyright (C) 1991  Lysator Academic Computer Association.
  *
  * This file is part of the LysKOM server.
@@ -26,7 +26,7 @@
 ** strerror.c
 */
 
-static char *rcsid = "$Id: strerror.c,v 0.6 1992/02/26 18:46:01 ceder Exp $";
+static char *rcsid = "$Id: strerror.c,v 0.7 1992/06/11 18:46:07 ceder Exp $";
 
 #include <string.h>
 #include <m-config.h>
@@ -36,9 +36,9 @@ static char *rcsid = "$Id: strerror.c,v 0.6 1992/02/26 18:46:01 ceder Exp $";
 #include <stdio.h>
 
 extern int sys_nerr;
-extern char *sys_errlist[];
+extern const char *sys_errlist[];
 
-char *strerror(int eno)
+const char *strerror(int eno)
 {
   static char buf[20];