Although perf depends on the libtraceevent, it cannot know when it needs
to be rebuilt. So just try to rebuild it always in order to make sure we
use the latest version.

While at it, silence annoying directory change messages.
Signed-off-by: Namhyung Kim <namhyung.kim@lge.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1337677434-4881-2-git-send-email-namhyung.kim@lge.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>