perf: Don't print traces when debugging ordering

Errors due to ordering bugs are easily lost in the middle
of traces.

When we are in this mode, don't print the traces so that
we don't miss the debugging messages.
But display a comforting message if we didn't encounter any
ordering problem.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>