Decoder segfault for Stereo at 24.4kbps in ivas_fec_noise_filling_fx()
# Basic info
<!--- Add commit SHA used to reproduce -->
- Float reference:
- Encoder (float): e15ad0addc0b0a429fcf05e1683e77c05164738a
- Decoder (float):
- Fixed point:
- Encoder (fixed):
- Decoder (fixed): d4fd91a6
# Bug description
The decoder crashes with a segfault:
{width=302 height=306}
`shr` calls `shr_o` with `Overflow` set to `NULL` eventually causing a null pointer dereference in `shl_o`.
# Ways to reproduce
Box folder: ...\Box_EXTERNAL_IVAS_BASOP_VERIFICATION\issues\issue-1344
<!-- Commandline or script -->
```bash
./IVAS_cod_flt_ref -stereo -max_band FB 24400 48 am1aa1s12_48.10dB.wav bit
eid-xor -vbr -fer bit stereo-mixed-music.am1aa1s12_ep.192 bit_err
# mono/stereo decoded to 32/48
./IVAS_dec_fx mono 32 bit_err out.wav
./IVAS_dec_fx stereo 48 bit_err out.wav
```
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issue