avcodec/aacsbr_fixed: Fix signed integer overflow in sbr_hf_inverse_filter()

Fixes: runtime error: signed integer overflow: 2147483584 + 128 cannot be represented in type 'int'
Fixes: 2164/clusterfuzz-testcase-minimized-4715936172998656

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