mkv.cpp: fix dirent issue with the recent "fixes"

modules/demux/mkv.cpp

@@ -47,6 +47,12 @@
 
 #ifdef HAVE_DIRENT_H
 #   include <dirent.h>
+#else if defined(MSCVER)
+extern "C" {
+void * vlc_opendir ( const char * ) ;
+void * vlc_readdir ( void * );
+int vlc_closedir ( void * ) ;
+}
 #endif
 
 /* libebml and matroska */
@@ -598,7 +604,7 @@ static int Open( vlc_object_t * p_this )
 
         if (p_src_dir != NULL)
         {
-            while ((p_file_item = readdir(p_src_dir)))
+            while ((p_file_item = (dirent *) readdir(p_src_dir)))
             {
                 if (strlen(p_file_item->d_name) > 4)
                 {