Fix memory leak when returning from method on error.

Fix memory leak when returning from method on error.

In ocstack.c, there was a method that could potentially malloc and then
return on error. I cleaned up this case. This fixes Rally TA5188.

Change-Id: I0ccd5259806c4e37b2ac73162f7ea0a7381fe4e7
Signed-off-by: Joseph Morrow <joseph.l.morrow@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/363
Reviewed-by: Erich Keane <erich.keane@intel.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Doug Hudson <douglas.hudson@intel.com>
Reviewed-by: Sudarshan Prasad <sudarshan.prasad@intel.com>