avfilter/xbr: remove FATE test entry from @todo

See 57688aecbd

libavfilter/vf_xbr.c

@@ -27,7 +27,7 @@
  * @see http://www.libretro.com/forums/viewtopic.php?f=6&t=134
  * @see https://github.com/yoyofr/iFBA/blob/master/fba_src/src/intf/video/scalers/xbr.cpp
  *
- * @todo add threading and FATE test
+ * @todo add threading
  */
 
 #include "libavutil/opt.h"