Fix compile warnings in SimpleClientServer for Linux

Fix compile warnings in SimpleClientServer for Linux

SimpleClientServer application for Linux was trying to check the address of array
'clientResponse->rcvdVendorSpecificHeaderOptions' which will always evaluate to 'true'.
Corrected by removing such checks in the code.

Change-Id: Id7306af0792646887740ab3c7952d5fffe8c760b
Signed-off-by: Ravi Nanjundappa <nravi.n@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/1454
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Erich Keane <erich.keane@intel.com>