fixed sample app defects detected by static analysis

fixed sample app defects detected by static analysis

fixed issues in CA sample app reported by static analysis tool

Change-Id: I1eaf0c6bedb0a86e8da7edf3301dcd06cb1ddfbf
Signed-off-by: hyuna0213.jo <hyuna0213.jo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/4401
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jaehong Jo <jaehong.jo@samsung.com>
Reviewed-by: Jon A. Cruz <jonc@osg.samsung.com>
(cherry picked from commit 391185941134848f6670f57dee2f458d60d49579)
Reviewed-on: https://gerrit.iotivity.org/gerrit/4537