avutil/buffer: Switch AVBuffer API to size_t

Announced in 14040a1d91.

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

libavdevice/decklink_enc.cpp

@@ -313,7 +313,7 @@ static void construct_cc(AVFormatContext *avctx, struct decklink_ctx *ctx,
     uint16_t *cdp_words;
     uint16_t len;
     uint8_t cc_count;
-    buffer_size_t size;
+    size_t size;
     int ret, i;
 
     const uint8_t *data = av_packet_get_side_data(pkt, AV_PKT_DATA_A53_CC, &size);