partrt: Improved tracing

When using info(), fail() or debug() functions, the messages will be added to
the trace as well.

Signed-off-by: Mats Liljegren <mats.liljegren@enea.com>
partrt: Added test_partrt_cpuset unit test suite

Signed-off-by: Mats Liljegren <mats.liljegren@enea.com>