Check against invalid i_title_timeout value.

src/video_output/video_output.c

@@ -1791,6 +1791,9 @@ static void DisplayTitleOnOSD( vout_thread_t *p_vout )
     const mtime_t i_start = mdate();
     const mtime_t i_stop = i_start + INT64_C(1000) * p_vout->p->i_title_timeout;
 
+    if( i_stop <= i_start )
+        return
+
     vlc_assert_locked( &p_vout->change_lock );
 
     vout_ShowTextAbsolute( p_vout, DEFAULT_CHAN,