Those functions are for checkinf if a given perf_hpp_fmt is a
filter-related sort entry.  With hierarchy mode, it needs to check
filters on the hist entries with its own hpp format list.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1457531222-18130-3-git-send-email-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>