perf tools: Don't display ignored entries on stdio ui

As for newt ui, don't display entries that have been marked
as ignored.

The practical current effect of this is to make parent
filtering really working. Before, entries that were ignored
were given a null parent but were still displayed. This
resulted in some weird effects:

 # Overhead      Command      Shared Object        Symbol
 # ........  ...........  .................  ............
 #
^A
                   |
                   --- __lock_acquire
                      |
                      |--95.97%-- lock_acquire
                      |          |
                      |          |--30.75%-- _raw_spin_lock

Discard these from the stdio display.

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: Stephane Eranian <eranian@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Sam Liao <phyomh@gmail.com>