tools lib traceevent: Modify header to work in C++ programs

Replace keyword "private" to "priv" in event-parse.h to allow it to be
used in C++ programs.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1345735321.5069.62.camel@gandalf.local.home


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>