Resolve "[CLANG18] ASAN: heap-buffer-overflow in lib_com/tools_fx.c:5450:25"

• Related issues: #2332 (closed)
• Requested reviewers: @kiene

Reason why this change is needed

• There is heap overflow in code.

Description of the change

• Use the existing precomputed array length (as it was already used a row below) to avoid issues. Also fixes other two similar cases in the same function.

Affected operating points

• Should be BE

Closes #2332 (closed)