Resolve #2272 "USAN: OOB indexing in tcx_ltp_pitch_search_ivas function"

• Related issues: #2272 (closed)
• Requested reviewers:

Closes #2272 (closed), #2279 (closed)

Reason why this change is needed

• Fix USAN complaint

Description of the change

• Calculate pointer offset directly when indexing into cor array instead of pre-setting a pointer which can go outside of the array boundaries

Affected operating points

• None, should be bitexact