Bluray: fix issue when libbluray couldn't parse the meta info

This is the case for BD of 2001
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/access/bluray.c

@@ -387,6 +387,9 @@ static int blurayControl(demux_t *p_demux, int query, va_list args)
         case DEMUX_GET_META:
         {
             struct meta_dl *meta = bd_get_meta(p_sys->bluray);
+            if(!meta)
+                return VLC_EGENERIC;
+
             vlc_meta_t *p_meta = (vlc_meta_t *) va_arg (args, vlc_meta_t*);
 
             if (!EMPTY_STR(meta->di_name)) vlc_meta_SetTitle(p_meta, meta->di_name);