perf hists: Remove parent filter check in DSO filter function

perf hists: Remove parent filter check in DSO filter function

The --exclude-other option sets HIST_FILTER__PARENT bit and it's only
set when a hist entry was created.  DSO filters don't change this so no
need to have the check in hists__filter_by_dso() IMHO.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Pekka Enberg <penberg@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1453252521-24398-1-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>