[libxml2] Fix compiler warning after 153cf15905cf4ec080612ada6703757d10caba1e

[Daniel Veillard <veillard src gnome org>]

commit 9c8eaabe83b9973ec97acecb5e499335397c523c
Author: Patrick Gansterer <paroga paroga com>
Date:   Fri Jan 4 12:41:53 2013 +0100

    Fix compiler warning after 153cf15905cf4ec080612ada6703757d10caba1e
    
    Add missing cast for xmlNop to silence a compiler warning.

 parser.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/parser.c b/parser.c
index e719c9f..31f90d6 100644
--- a/parser.c
+++ b/parser.c
@@ -2025,7 +2025,7 @@ static void xmlSHRINK (xmlParserCtxtPtr ctxt) {
 static void xmlGROW (xmlParserCtxtPtr ctxt) {
     if ((((ctxt->input->end - ctxt->input->cur) > XML_MAX_LOOKUP_LIMIT) ||
          ((ctxt->input->cur - ctxt->input->base) > XML_MAX_LOOKUP_LIMIT)) &&
-         ((ctxt->input->buf) && (ctxt->input->buf->readcallback != xmlNop)) &&
+         ((ctxt->input->buf) && (ctxt->input->buf->readcallback != (xmlInputReadCallback) xmlNop)) &&
         ((ctxt->options & XML_PARSE_HUGE) == 0)) {
         xmlFatalErr(ctxt, XML_ERR_INTERNAL_ERROR, "Huge input lookup");
         ctxt->instate = XML_PARSER_EOF;