Eliminate result code from RCSGetResponse and RCSSetResponse.

Eliminate result code from RCSGetResponse and RCSSetResponse.

It turned out there is no reason for users to set the result code.
The only scenario that RCSResponses have not OK for the result is that there is an error occurred
and in that case it should be an exception on resource-encapsulation layer.

Change-Id: Icef409ea5e224f9f02e12e174231baa4e11c5a33
Signed-off-by: coderhyme <jhyo.kim@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/2705
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Madan Lanka <lanka.madan@samsung.com>