MPE_Init_log - Initialize the logging of events.
This routine must be called before any of the other MPE logging routines. It is
a collective call over 'MPI_COMM_WORLD'. MPE_Init_log() & MPE_Finish_log()
are NOT needed when liblmpe.a is linked because MPI_Init() would have called
MPE_Init_log() already. liblmpe.a will be included in the link path if either
"mpicc -mpe=mpilog" or "mpecc -mpilog" is used in the link
step.
This function is threadsafe, but MPE_Init_log() is expected to be
called on only one thread in each process. This thread will be labelled as
main thread.
Always return MPE_LOG_OK.