avcodec/ttadata: Add sentinel at the end of ff_tta_shift_1

Fixes: out of array access
Fixes: 34933/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TTA_fuzzer-5629322560929792

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/ttadata.c

@@ -30,7 +30,8 @@ const uint32_t ff_tta_shift_1[] = {
     0x01000000, 0x02000000, 0x04000000, 0x08000000,
     0x10000000, 0x20000000, 0x40000000, 0x80000000,
     0x80000000, 0x80000000, 0x80000000, 0x80000000,
-    0x80000000, 0x80000000, 0x80000000, 0x80000000
+    0x80000000, 0x80000000, 0x80000000, 0x80000000,
+    0xFFFFFFFF
 };
 
 const uint32_t * const ff_tta_shift_16 = ff_tta_shift_1 + 4;