avcodec/v410enc: do not use internal->byte_buffer

it is not optimal when the buffer size is well known at allocation time

This avoids a memcpy()

about 1% faster
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/v410enc.c

@@ -43,7 +43,8 @@ static int v410_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
     uint32_t val;
     int i, j, ret;
 
-    if ((ret = ff_alloc_packet2(avctx, pkt, avctx->width * avctx->height * 4, 0)) < 0)
+    if ((ret = ff_alloc_packet2(avctx, pkt, avctx->width * avctx->height * 4,
+                                            avctx->width * avctx->height * 4)) < 0)
         return ret;
     dst = pkt->data;