USAN: index out of bounds in OSBA JBM decoding to mono and stereo with rate switching
### Basic info
- Commit SHA: 6a18db2368f6380c492a85fa02decbb2ac1a2aeb
### Bug description
Clang usan sanitizer test in pipeline found an error:
<!--- Copy sanitizer traceback from command line here -->
```
lib_dec/ivas_jbm_dec.c:2545:28: runtime error: index 8 out of bounds for type 'int16_t [8]'
SUMMARY: UndefinedBehaviorSanitizer: out-of-bounds-index lib_dec/ivas_jbm_dec.c:2545:28 in
```
<!--- Copy test job URL here -->
Link to test pipeline: https://forge.3gpp.org/rep/ivas-codec-pc/ivas-codec/-/jobs/205521
### Ways to reproduce
Using the [scripts](https://forge.3gpp.org/rep/ivas-codec-pc/ivas-codec/-/wikis/Software-development/pyivastest-howto#how-to-reproduce-tests):
<!--- check correct sanitizer type -->
<!--- add error pattern if needed -->
JBM profile file is here: [jbm_err_profile.dat](/uploads/9532bfb4dd0ef4f1d801390506bc3bb0/jbm_err_profile.dat)
```
python3 scripts/IvasBuildAndRunChecks.py --checks CLANG3 -m OSBA_ISM2_FOA_ball_fb_rs -p /path/to/my/local/ci_linux_ltv_local.json --usan_supp_file scripts/ubsan.supp -J jbm_err_profile.dat
```
or directly:
```
make clean
make -j CLANG=3
./IVAS_cod -ism_sba 2 1 NULL NULL -max_band fb scripts/switchPaths/sw_13k2_512k.bin 48 ltv48_OSBA_2ISM_FOA.wav bit
networkSimulator jbm_err_profile.dat bit bit_jbm tracefile 2
./IVAS_dec -Tracefile tracefile -VOIP mono 48 bit_jbm out.wav
```
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issue