perf ordered_events: Rework show_progress for __ordered_events__flush

perf ordered_events: Rework show_progress for __ordered_events__flush

Decide to use the progress bar one level higher, we will need this in
following patch.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/n/tip-ocjdukp2a8ujikkmafd0j5zv@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>