avcodec/aacdec: Check if we run out of input in read_stream_mux_config()

Fixes: Infinite loop
Fixes: 16920/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AAC_LATM_fuzzer-5653421289373696

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 3dce4d03d5)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/aacdec.c

@@ -411,6 +411,8 @@ static int read_stream_mux_config(struct LATMContext *latmctx,
             } else {
                 int esc;
                 do {
+                    if (get_bits_left(gb) < 9)
+                        return AVERROR_INVALIDDATA;
                     esc = get_bits(gb, 1);
                     skip_bits(gb, 8);
                 } while (esc);