Sanitizer issue in IGF with bitrate switch in SBA encoding mode

Basic info

• Commit SHA:

Bug description

Clang (msan/asan?) sanitizer test in pipeline found an error:

Link to test pipeline: XXX

Ways to reproduce

#!/bin/bash
git clone -b longer-testv-on-runners --single-branch https://forge.3gpp.org/rep/ivas-codec-pc/ivas-pc-testfiles.git
cd ivas-pc-testfiles
# we need to create a 32 kHz version
for f in $(ls ltv48*); do sox $f -r 32000 ${f/48/32}; done
cd -
cp ivas-pc-testfiles/* scripts/testv/ # needed for the 32 kHz ltv we just created
make -j CLANG=1 # or use normally compiled binaries with valgrind (see below)
./IVAS_cod -dtx -sba 3 scripts/switchPaths/sw_13k2_to_128k_10fr.bin 32 scripts/testv/ltv32_HOA3.wav hoa3.192


Frames processed:       5055    ==28050==WARNING: MemorySanitizer: use-of-uninitialized-value

0x7f55eb8250ed in IGF_CalculateEnvelope /ivas-codec/lib_enc/igf_enc.c:427:41

0x7f55eb823710 in IGFEncApplyMono /ivas-codec/lib_enc/igf_enc.c:1894:5

0x7f55eb67cd7c in ProcessIGF /ivas-codec/lib_enc/tcx_utils_enc.c:1472:5

0x7f55eb8e87b3 in ivas_mct_core_enc /ivas-codec/lib_enc/ivas_mct_core_enc.c:434:25

0x7f55eb395131 in ivas_mct_enc /ivas-codec/lib_enc/ivas_mct_enc.c:247:5

0x7f55eb2a827e in ivas_enc /ivas-codec/lib_enc/ivas_enc.c:272:28

0x7f55eb1f21a7 in IVAS_ENC_EncodeFrameToSerial /ivas-codec/lib_enc/lib_enc.c:1343:24

0x7f55eb1cfa05 in main /ivas-codec/apps/encoder.c:782:24

0x7f55eadb9d8f in __libc_start_call_main csu/../sysdeps/nptl/libc_start_call_main.h:58:16

0x7f55eadb9e3f in __libc_start_main csu/../csu/libc-start.c:392:3

0x7f55eb1425b4 in _start (/ivas-codec/IVAS_cod+0x235b4) (BuildId: 626bdbaaa2c5176d2495c858c366d35f70e65527)`

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