avcodec/sbrdsp_fixed: Return an error from sbr_hf_apply_noise() if operations are impossible

Fixes: 1775/clusterfuzz-testcase-minimized-5330288148217856

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