avfilter/tonemap_vaapi: set va parameters filters and numbers

This can fill VAProcPipelineParameterBuffer correctly and make the
pipeline works.
Reviewed-by: Soft Works <softworkz@hotmail.com>
Signed-off-by: Fei Wang <fei.w.wang@intel.com>
Signed-off-by: Haihao Xiang <haihao.xiang@intel.com>

libavfilter/vf_tonemap_vaapi.c

@@ -294,6 +294,11 @@ static int tonemap_vaapi_filter_frame(AVFilterLink *inlink, AVFrame *input_frame
     if (err < 0)
         goto fail;
 
+    if (vpp_ctx->nb_filter_buffers) {
+        params.filters = &vpp_ctx->filter_buffers[0];
+        params.num_filters = vpp_ctx->nb_filter_buffers;
+    }
+
     err = ff_vaapi_vpp_render_picture(avctx, &params, output_frame);
     if (err < 0)
         goto fail;