avformat/anm: use ff_get_extradata()

libavformat/anm.c

@@ -132,12 +132,7 @@ static int read_header(AVFormatContext *s)
     avio_skip(pb, 58);
 
     /* color cycling and palette data */
-    st->codecpar->extradata_size = 16*8 + 4*256;
-    st->codecpar->extradata      = av_mallocz(st->codecpar->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
-    if (!st->codecpar->extradata) {
-        return AVERROR(ENOMEM);
-    }
-    ret = avio_read(pb, st->codecpar->extradata, st->codecpar->extradata_size);
+    ret = ff_get_extradata(s, st->codecpar, s->pb, 16*8 + 4*256);
     if (ret < 0)
         return ret;