csdk: Fix compiler warnings in ocresource.c

csdk: Fix compiler warnings in ocresource.c

-Wunused-parameter - fixed using the OC_UNUSED macro
-Wtype-limits - the statment `if (dimensions[0] >= 0)` is
always true because the `dimensions` param  is size_t
which is never negative. Since its always true the if
statment was removed.

Change-Id: I08c9e68e9c688cd9f31bee8d9368a4eec6c8cc01
Signed-off-by: George Nash <george.nash@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/17815
Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Mike Fenelon <mike.fenelon@microsoft.com>
Reviewed-by: Dan Mihai <Daniel.Mihai@microsoft.com>