perf stat: Use perf_evlist__prepare/start_workload()

The perf stat had an open code to the duplicated work.  Use the helper
as it now can be called without struct perf_record_opts.

Signed-off-by: Namhyung Kim <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
1 file changed