Merge commit '28c020d4'

* commit '28c020d4':
  matroskaenc: check avio_open_dyn_buf return value

Conflicts:
	libavformat/matroskaenc.c

See: b1f517f5Merged-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/matroskaenc.c

@@ -1693,7 +1693,8 @@ static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt, int add_
 
     if (!s->pb->seekable) {
         if (!mkv->dyn_bc) {
-            if ((ret = avio_open_dyn_buf(&mkv->dyn_bc)) < 0) {
+            ret = avio_open_dyn_buf(&mkv->dyn_bc);
+            if (ret < 0) {
                 av_log(s, AV_LOG_ERROR, "Failed to open dynamic buffer\n");
                 return ret;
             }