avformat/rl2: use ff_get_extradata()

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

libavformat/rl2.c

@@ -127,13 +127,9 @@ static av_cold int rl2_read_header(AVFormatContext *s)
     if(signature == RLV3_TAG && back_size > 0)
         st->codec->extradata_size += back_size;
 
-    if(ff_alloc_extradata(st->codec, st->codec->extradata_size))
+    if(ff_get_extradata(st->codec, pb, st->codec->extradata_size) < 0)
         return AVERROR(ENOMEM);
 
-    if(avio_read(pb,st->codec->extradata,st->codec->extradata_size) !=
-                      st->codec->extradata_size)
-        return AVERROR(EIO);
-
     /** setup audio stream if present */
     if(sound_rate){
         if (!channels || channels > 42) {