libvpx: Pull from upstream

source/libvpx/vpx/src/vpx_encoder.c

 /*
  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 376 matching lines @@
 
 
 const vpx_codec_cx_pkt_t *vpx_codec_pkt_list_get(struct vpx_codec_pkt_list *list,
                                                  vpx_codec_iter_t           *iter) {
   const vpx_codec_cx_pkt_t *pkt;
 
   if (!(*iter)) {
     *iter = list->pkts;
   }
 
-  pkt = (const void *) * iter;
+  pkt = (const vpx_codec_cx_pkt_t *)*iter;
 
   if ((size_t)(pkt - list->pkts) < list->cnt)
     *iter = pkt + 1;
   else
     pkt = NULL;
 
   return pkt;
 }