libgsm: switch to ff_alloc_packet2().

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/libgsm.c

@@ -100,8 +100,7 @@ static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
     gsm_signal *samples = (gsm_signal *)frame->data[0];
     struct gsm_state *state = avctx->priv_data;
 
-    if ((ret = ff_alloc_packet(avpkt, avctx->block_align))) {
-        av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
+    if ((ret = ff_alloc_packet2(avctx, vpkt, avctx->block_align))) {
         return ret;
     }