lavc/vvc_parser: Fixed the has_b_frames setting

has_b_frames used in decoder for size of the frame reordering
buffer, setting this field from dpb_max_num_reorder_pics.

Signed-off-by: Jun Zhao <barryjzhao@tencent.com>

libavcodec/vvc_parser.c

@@ -185,8 +185,8 @@ static void set_parser_ctx(AVCodecParserContext *s, AVCodecContext *avctx,
     avctx->color_range =
         sps->vui.vui_full_range_flag ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
 
-    avctx->has_b_frames = (sps->sps_max_sublayers_minus1 + 1) > 2 ? 2 :
-                           sps->sps_max_sublayers_minus1;
+    avctx->has_b_frames =
+        sps->sps_dpb_params.dpb_max_num_reorder_pics[sps->sps_max_sublayers_minus1];
 
     if (sps->sps_ptl_dpb_hrd_params_present_flag &&
         sps->sps_timing_hrd_params_present_flag) {