opus_parser: fix leaking channel_maps on error

Make ff_opus_parse_extradata free allocated memory on error instead of
expecting callers to free it in that case.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

libavcodec/opus.c

@@ -403,6 +403,7 @@ av_cold int ff_opus_parse_extradata(AVCodecContext *avctx,
         } else if (idx >= streams + stereo_streams) {
             av_log(avctx, AV_LOG_ERROR,
                    "Invalid channel map for output channel %d: %d\n", i, idx);
+            av_freep(&s->channel_maps);
             return AVERROR_INVALIDDATA;
         }
 

libavcodec/opusdec.c

@@ -646,7 +646,6 @@ static av_cold int opus_decode_init(AVCodecContext *avctx)
     /* find out the channel configuration */
     ret = ff_opus_parse_extradata(avctx, c);
     if (ret < 0) {
-        av_freep(&c->channel_maps);
         av_freep(&c->fdsp);
         return ret;
     }