perf bench sched-messaging: Drop barf()

Instead of reinventing the wheel, we can use err(2) when dealing with
fatal errors. Exit code is now always EXIT_FAILURE (1).

Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1402942467-10671-9-git-send-email-davidlohr@hp.com


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