avcodec/sbrdsp_fixed: Fix integer overflow in shift in sbr_hf_g_filt_c()

Fixes: runtime error: shift exponent 66 is too large for 64-bit type 'long long'
Fixes: 3642/clusterfuzz-testcase-minimized-5443853801750528

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