avformat/mp3dec: read xing toc independant of usetoc, only skip filling index if requested

Fixes hypothetical parsing bug with -usetoc 0
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/mp3dec.c

@@ -94,9 +94,6 @@ static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration
     int i;
     MP3DecContext *mp3 = s->priv_data;
 
-    if (!mp3->usetoc)
-        return;
-
     if (!filesize &&
         !(filesize = avio_size(s->pb))) {
         av_log(s, AV_LOG_WARNING, "Cannot determine file size, skipping TOC table.\n");
@@ -105,8 +102,8 @@ static void read_xing_toc(AVFormatContext *s, int64_t filesize, int64_t duration
 
     for (i = 0; i < XING_TOC_COUNT; i++) {
         uint8_t b = avio_r8(s->pb);
-
-        av_add_index_entry(s->streams[0],
+        if (mp3->usetoc)
+            av_add_index_entry(s->streams[0],
                            av_rescale(b, filesize, 256),
                            av_rescale(i, duration, XING_TOC_COUNT),
                            0, 0, AVINDEX_KEYFRAME);