Remove unused/deprecated code

:Release Notes:
Remove unused/deprecated code

:Detailed Notes:
Some coverity issues refers to unused code which requires
re-factoring. But since there is no place where these function used we
can't ensure correct behaviour and there is no reason for keeping that
dead code. Probably this code duplicated in some other service chopped
off from luna-sysservice. At least some of them became part of LS2 API
(like LSSubscriptionProcess/LSSubscriptionRespond).
So we remove unused function related with luna subscribers list
manipulations.
Removed coverity issues:
- CID 14719: Passing null pointer "serviceHandlePublic" to function
  "LSSubscriptionAcquire(LSHandle *, char const *, LSSubscriptionIter
  **, LSError *)", which dereferences it.
- CID 14720: Passing null pointer "serviceHandlePublic" to function
  "LSSubscriptionAcquire(LSHandle *, char const *, LSSubscriptionIter
  **, LSError *)", which dereferences it.
- CID 14721: Passing null pointer "serviceHandlePublic" to function
  "LSSubscriptionAcquire(LSHandle *, char const *, LSSubscriptionIter
  **, LSError *)", which dereferences it.
- CID 14722: Passing null pointer "serviceHandlePublic" to function
  "LSSubscriptionAcquire(LSHandle *, char const *, LSSubscriptionIter
  **, LSError *)", which dereferences it.

:Testing Performed:
Both desktop and OE builds succeed.

:QA Notes:

:Issues Addressed:
[GF-53290] scrub rest of luna-sysservice issues reported by coverity

Open-webOS-DCO-1.0-Signed-off-by: Nikolay Orliuk <nikolay.orliuk@lge.com>
Change-Id: I6e662df678b060e40c7d810e3706a98051e63133
Reviewed-on: https://g2g.palm.com/4068
Reviewed-by: DCO Verification
Reviewed-by: Mykola Kryvonos <mykola.kryvonos@lge.com>
Tested-by: Mykola Kryvonos <mykola.kryvonos@lge.com>