Convert acl_check_sys_cmd test to CppUTest

Convert [acl_check_sys_cmd_test](https://github.com/intel/fpga-runtime-for-opencl/blob/bd7f1073b7a85858b5180a3329a01286f34bc8d8/lib/acl_check_sys_cmd/test/acl_check_sys_cmd_test.cpp) to use CppUTest for consistency with other tests.

See also https://github.com/intel/fpga-runtime-for-opencl/pull/121