utvideoenc/v410enc: do not set AVFrame.reference.

That field will be deprecated.

libavcodec/utvideoenc.c

@@ -598,7 +598,6 @@ static int utvideo_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
      * At least currently Ut Video is IDR only.
      * Set flags accordingly.
      */
-    avctx->coded_frame->reference = 0;
     avctx->coded_frame->key_frame = 1;
     avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
 

libavcodec/v410enc.c

@@ -56,7 +56,6 @@ static int v410_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
     }
     dst = pkt->data;
 
-    avctx->coded_frame->reference = 0;
     avctx->coded_frame->key_frame = 1;
     avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;