Fixed shift-negative-value warning

Fixed shift-negative-value warning

The compilar was interpreting the number zero '0' as a
signed number not an unsigned number. The left shift behavior
for signed numbers is undefined. The 'u' sufix was added to
tell the compilar that the '0' is an unsigned number.

Change-Id: Ida6c5c5ee2a7ea556755ca55d71858469a0691ac
Signed-off-by: George Nash <george.nash@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/11525
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Larry Sachs <larry.j.sachs@intel.com>
Reviewed-by: jaehyun Cho <jaehyun3.cho@samsung.com>
Reviewed-by: Rick Bell <richard.s.bell@intel.com>