ftracetest: Add instance created, delete, read and enable event test

ftracetest: Add instance created, delete, read and enable event test

Add a new ftrace test that creates three threads. One that creates and
removes an ftrace instance, one that reads the instance, and one that enables
and disables events in the instance. This is a stress test for accessing and
removing instances at the same time.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>