Wrong index boundary checking in `bta_av_api_reg_sep` (IDFGH-16991)

[kienhg96]

Answers checklist.

• I have read the documentation ESP-IDF Programming Guide and the issue is not addressed there.
• I have updated my IDF branch (master or release) to the latest version and checked that the issue is present there.
• I have searched the issue tracker for a similar issue and not found a similar issue.

General issue report

The index boundary checking at bta_av_main.c#L766 is incorrect.
It is checking great than instead of great or equal.
It should be: if (index >= BTA_AV_MAX_SEPS || ...

[Finney-esp]

Yes, you are right. We will fix it soon. Thanks!