Cyclictests cleanup make work with new kernel

[rlrevell]

Hey, I had need for some RT testing utils recently, and found these somewhat bitrotted but still quite valuable. I got them to compile with a modern kernel and dropped support for everything else. These tracing tools have been around for 10-20 years, which should have been plenty of time to design an API around this stuff.

I then dealt with a bunch of GCC warnings, a few pedantries, as well as some potential buffer overflows. All of the utilities at least compile and run for 20-30 seconds without crashing. The testing gets sparser as you move away from cyclictest.

I have a few more RT primitives that I'd like to add coverage for, namely, using pthread synchronization primitives along with memlock()ed shared memory for IPC, and I discovered some cool RT-relevant things about how pthreads are implemented that I never had time to follow through on