qdm2: fix incorrect error spam

Fixes Ticket1375
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/qdm2.c

@@ -1363,6 +1363,7 @@ static void qdm2_fft_decode_tones (QDM2Context *q, int duration, GetBitContext *
         if (q->superblocktype_2_3) {
             while ((n = qdm2_get_vlc(gb, &vlc_tab_fft_tone_offset[local_int_8], 1, 2)) < 2) {
                 if (get_bits_left(gb)<0) {
+                    if(local_int_4 < q->group_size)
                         av_log(0, AV_LOG_ERROR, "overread in qdm2_fft_decode_tones()\n");
                     return;
                 }