dash: Fixing a crash with invalid XML documents.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>
(cherry picked from commit 5e7910c3)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/stream_filter/dash/xml/DOMParser.cpp

@@ -71,7 +71,7 @@ Node*   DOMParser::processNode              ()
 {
     const char *data;
     int type = xml_ReaderNextNode(this->vlc_reader, &data);
-    if(type != XML_READER_TEXT && type != XML_READER_NONE && type != XML_READER_ENDELEM)
+    if(type != -1 && type != XML_READER_TEXT && type != XML_READER_NONE && type != XML_READER_ENDELEM)
     {
         Node *node = new Node();