This is the first function that a program using the library
must call otherwise the library will not function at all.
This function will probe the host CPU and automatically
detect which PMU it has. All internal data structures will
be initialized as a result of this call. In the case of
a multi-threaded application, this function needs to be called
only once, most likely by the initial thread.
The function returns whether or not it was successful, i.e., the
host PMU has been correctly identified and is supported. A return
value of PFMLIB_SUCCESS indicates success, otherwise the value is
an error code.