krb5_auth: fix my previous change to compile

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

 *

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

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

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

 * Copyright (c) 2004 - 2009 Daniel Stenberg

 * All rights reserved.

{

  int ret;

  char *p;

  const char *host = conn->host->name;

  const char *host = conn->host.name;

  ssize_t nread;

  curl_socklen_t l = sizeof(conn->local_addr);

  struct SessionHandle *data = conn->data;