avcodec/pthread_frame: Remove FF_API_SLICE_OFFSET

Since 432adca5fe no decoder
looks at the slice_count and slice_offset fields at all,
so there is no reason to synchronize them between the worker
and the user thread.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/pthread_frame.c

@@ -424,22 +424,6 @@ FF_ENABLE_DEPRECATION_WARNINGS
 FF_DISABLE_DEPRECATION_WARNINGS
     dst->reordered_opaque = src->reordered_opaque;
 FF_ENABLE_DEPRECATION_WARNINGS
-#endif
-
-#if FF_API_SLICE_OFFSET
-FF_DISABLE_DEPRECATION_WARNINGS
-    if (src->slice_count && src->slice_offset) {
-        if (dst->slice_count < src->slice_count) {
-            int err = av_reallocp_array(&dst->slice_offset, src->slice_count,
-                                        sizeof(*dst->slice_offset));
-            if (err < 0)
-                return err;
-        }
-        memcpy(dst->slice_offset, src->slice_offset,
-               src->slice_count * sizeof(*dst->slice_offset));
-    }
-    dst->slice_count = src->slice_count;
-FF_ENABLE_DEPRECATION_WARNINGS
 #endif
 
     av_packet_unref(dst->internal->last_pkt_props);
@@ -756,12 +740,6 @@ void ff_frame_thread_free(AVCodecContext *avctx, int thread_count)
                 av_freep(&ctx->priv_data);
             }
 
-#if FF_API_SLICE_OFFSET
-FF_DISABLE_DEPRECATION_WARNINGS
-            av_freep(&ctx->slice_offset);
-FF_ENABLE_DEPRECATION_WARNINGS
-#endif
-
             av_buffer_unref(&ctx->internal->pool);
             av_packet_free(&ctx->internal->last_pkt_props);
             av_freep(&ctx->internal);