avfilter/vf_swapuv: Remove empty options and AVClass

This filter only had an AVClass and empty options because up until
recently, avfilter_init_str() errored out when options were provided
for a filter without an AVClass. But setting (generic) options is
necessary to take advantage of timeline support. So with
avfilter_init_str() fixed, the AVClass and the options can be removed.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavfilter/vf_swapuv.c

@@ -23,23 +23,12 @@
  * swap UV filter
  */
 
-#include "libavutil/opt.h"
 #include "libavutil/pixdesc.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"
 
-typedef struct SwapUVContext {
-    const AVClass *class;
-} SwapUVContext;
-
-static const AVOption swapuv_options[] = {
-    { NULL }
-};
-
-AVFILTER_DEFINE_CLASS(swapuv);
-
 static void do_swap(AVFrame *frame)
 {
     FFSWAP(uint8_t*,     frame->data[1],     frame->data[2]);
@@ -104,8 +93,6 @@ static const AVFilterPad swapuv_inputs[] = {
 const AVFilter ff_vf_swapuv = {
     .name          = "swapuv",
     .description   = NULL_IF_CONFIG_SMALL("Swap U and V components."),
-    .priv_size     = sizeof(SwapUVContext),
-    .priv_class    = &swapuv_class,
     FILTER_INPUTS(swapuv_inputs),
     FILTER_OUTPUTS(ff_video_default_filterpad),
     FILTER_QUERY_FUNC(query_formats),