Fix memory leak of mprobe

Fix memory leak of mprobe

 - When mcheck () fails in MRP_INIT time and then mprobe () returns MCHECK_DISABLED, which needs
   to free memory otherwise occur abnormal memory corruption.
   For more detailed, MRP_INIT (memory_check_init) is executed in the parent process of forking and
   __passthru_free is executed in the child process. So variable (mcheck_result) is unnecessary because
   we can consider mprobe returns always only MCHECK_DISABLED and mcheck is not performed at child process.

Change-Id: I123d3af30cb1b84b34b09349952a225ee0ec91ad