Resolved Klocwork warnings for C++ Stack & Samples

Resolved Klocwork warnings for C++ Stack & Samples

Fixed comment, space issue and added default case to switch in
groupclient.cpp

Made code compliance to code guideline

Resolve Infinite loop warning and Memory leak warning.
Also replaced multiple if-else with switch to match code
standards.

Change-Id: I125ab9d20fe4c8352f261afa7a538a7487aa7880
Signed-off-by: Shilpa Sodani <shilpa.a.sodani@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/141
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Erich Keane <erich.keane@intel.com>
Reviewed-by: Sudarshan Prasad <sudarshan.prasad@intel.com>