Fix out of bound reads in the QDM2 decoder.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Signed-off-by: Justin Ruggles <justin.ruggles@gmail.com>
(cherry picked from commit 5a19acb17c)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>
(cherry picked from commit 0d93d5c461)

Signed-off-by: Reinhard Tartler <siretart@tauware.de>

libavcodec/qdm2.c

@@ -1378,6 +1378,8 @@ static void qdm2_fft_decode_tones (QDM2Context *q, int duration, GetBitContext *
             return;
 
         local_int_14 = (offset >> local_int_8);
+        if (local_int_14 >= FF_ARRAY_ELEMS(fft_level_index_table))
+            return;
 
         if (q->nb_channels > 1) {
             channel = get_bits1(gb);