Fixing client smack tests.
[Issue#] SSDWSSP-543
[Bug/Feature] Root privileges are dropped in main test process and remaining
tests in SECURITY_SERVER_TESTS_CLIENT_SMACK group run with them
and fail when line with RUNNER_IGNORED_MSG deleted.
[Cause] Changing test macros from RUNNER_CHILD* to RUNNER_MULTIPROCESS*
on one smack and one nosmack test resulted in passing dropped
root privileges in main process to tests run after those. Those
privileges were held by RUNNER_CHILD* macros.
[Solution] Keeping that macros for collecting result puposes and running
both processes droping root privilege in child.
[Verification] Building and running security-tests.sh ss-clientsmack. No tests
should fail.
Change-Id: I7b1b4974dedd9a9d1d96e952411aa01cd4f3399b