demux/playlist/itml: remove usage of fprintf

This diagnostic is not helpful, and should definitely not use fprintf
(as such it is removed).

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/demux/playlist/itml.c

@@ -366,7 +366,6 @@ static track_elem_t *new_track()
 
 static void free_track( track_elem_t *p_track )
 {
-    fprintf( stderr, "free track\n" );
     if ( !p_track )
         return;