compiler warnings fixed

/* GSSAPI/krb5 support for FTP - loosely based on old krb4.c

 *

 * Copyright (c) 1995, 1996, 1997, 1998, 1999, 2010 Kungliga Tekniska Hgskolan

 * Copyright (c) 1995, 1996, 1997, 1998, 1999 Kungliga Tekniska Hgskolan

 * (Royal Institute of Technology, Stockholm, Sweden).

 * Copyright (c) 2004 - 2009 Daniel Stenberg

 * Copyright (c) 2004 - 2011 Daniel Stenberg

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

static int

krb5_overhead(void *app_data, int level, int len)

{

  /* no arguments are used, just init them to prevent compiler warnings */

  app_data = NULL;

  level = 0;

  len = 0;

  /* no arguments are used */

  (void)app_data;

  (void)level;

  (void)len;

  return 0;

}