MKV : Fix some memory leaks in the EBML parser.

Signed-off-by: Rémi Duraffort <ivoire@videolan.org>

modules/demux/mkv/Ebml_parser.cpp

@@ -47,7 +47,13 @@ EbmlParser::EbmlParser( EbmlStream *es, EbmlElement *el_start, demux_t *p_demux
 
 EbmlParser::~EbmlParser( void )
 {
-    for( int i = 1; i < mi_level; i++ )
+    if( !mi_level )
+    {
+        delete m_el[1];
+        return;
+    }
+
+    for( int i = 1; i <= mi_level; i++ )
     {
         if( !mb_keep )
         {