Fix build issue caused by #16731

Fix build issue caused by #16731

Patchset #16731 changed callback API, and then some time it wasn't rebased.
During that time CA API tests were updated, and old callback API were used.
Gerrit showed no conflicts, Jenkins build were successful.
It is required to rebase more frequently.

I've fixed build error + fix compiler warnings in that file.

Change-Id: I360f22cba5ec70075eff4f814f319678bbf099c8
Signed-off-by: Andrii Shtompel <a.shtompel@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/18481
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Kevin Kane <kkane@microsoft.com>