avcodec: Remove sidedata-only-packet cruft

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/flacenc.c

@@ -1370,13 +1370,7 @@ static int flac_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
         av_md5_final(s->md5ctx, s->md5sum);
         write_streaminfo(s, avctx->extradata);
 
-#if FF_API_SIDEDATA_ONLY_PKT
-FF_DISABLE_DEPRECATION_WARNINGS
-        if (avctx->side_data_only_packets && !s->flushed) {
-FF_ENABLE_DEPRECATION_WARNINGS
-#else
         if (!s->flushed) {
-#endif
             uint8_t *side_data = av_packet_new_side_data(avpkt, AV_PKT_DATA_NEW_EXTRADATA,
                                                          avctx->extradata_size);
             if (!side_data)