decoder/flac: pass VorbisComment to flac_parse_replay_gain()

src/decoder/plugins/FlacCommon.cxx

@@ -98,7 +98,7 @@ void flac_metadata_common_cb(const FLAC__StreamMetadata * block,
 		break;
 
 	case FLAC__METADATA_TYPE_VORBIS_COMMENT:
-		if (flac_parse_replay_gain(rgi, block))
+		if (flac_parse_replay_gain(rgi, block->data.vorbis_comment))
 			decoder_replay_gain(data->decoder, &rgi);
 
 		decoder_mixramp(data->decoder, flac_parse_mixramp(block));

src/decoder/plugins/FlacMetadata.cxx

@@ -55,11 +55,8 @@ vorbis_comment_value(const FLAC__StreamMetadata *block,
 
 bool
 flac_parse_replay_gain(ReplayGainInfo &rgi,
-		       const FLAC__StreamMetadata *block)
+		       const FLAC__StreamMetadata_VorbisComment &vc)
 {
-	const FLAC__StreamMetadata_VorbisComment &vc =
-		block->data.vorbis_comment;
-
 	rgi.Clear();
 
 	bool found = false;

src/decoder/plugins/FlacMetadata.hxx

@@ -116,7 +116,7 @@ struct ReplayGainInfo;
 
 bool
 flac_parse_replay_gain(ReplayGainInfo &rgi,
-		       const FLAC__StreamMetadata *block);
+		       const FLAC__StreamMetadata_VorbisComment &vc);
 
 MixRampInfo
 flac_parse_mixramp(const FLAC__StreamMetadata *block);