Resolve "Use of calloc() in BASOP"

• Related issues: #2431 (closed)
• Requested reviewers:

Reason why this change is needed

• The use of calloc() should be avoided in the BASOP framework, similarly to the FLP framework.

Description of the change

• Avoid use of calloc()
• Remove buffer st->L_mem_hp_out_fx[] which is not explicitly initialized and is anyway missing in FLP

Affected operating points

• All is BE.

Closes #2431 (closed)