Updated test_system_multi_process.c to validate throughput against 2 kinetic...

Updated test_system_multi_process.c to validate throughput against 2 kinetic devices from 2 seperate processes/daemons.
NOTE: The drive apparently has an issue with processing very short keys (4 bytes) causing low throughput. Bump up to 8 bytes fixes performance issue in this test. Needs further investigation.