perf session: Separate progress bar update when processing events

Currently when processing events in the __perf_session__process_events
function we update a progress bar based on the file_size. During the
same processing we update the progress bar from within
flush_sample_queue which is based on number of samples count.

Having 2 different based updates is causing the progress bar to jump
heavily back and forth giving not much usefull info.

Fixing this by keeping only __perf_session__process_events based
progress bar update. And turning on flush_sample_queue progress bar
update only for final flushing.

This reduces the number of time the progress bar update function is
called and it significantly reduces the loading time for TUI, where the
progress bar update takes quite a lot of time.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130905091449.GC1100@krava.brq.redhat.com


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