Resolve "[CLANG18] MSAN: use-of-uninitialized-value in lib_dec/ivas_mc_param_dec_fx.c:3409:26"

• Related issues: #2384 (closed)
• Requested reviewers: ???

Reason why this change is needed

Reading of uninitialized memory from Cy_buf_e[k] when doing renormalization.

Description of the change

Only read initialized values of Cy_buf_e[k].

Affected operating points

All BE

Closes #2384 (closed)