perf report: Relax -g option parsing not to limit the option order

perf report: Relax -g option parsing not to limit the option order

Current perf report -g/--call-graph option parser requires for option
argument having following order:

  type,min_percent[,print_limit],order,key

But sometimes it's annoying to type all even if one just wants to change
the "order" or "key" setting.

This patch fixes it to remove the ordering restriction so that one can
use just "-g caller", for instance.  The only remaining restriction is
that the "print_limit" always comes after the "min_percent".

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Arun Sharma <asharma@fb.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Rodrigo Campos <rodrigo@sdfg.com.ar>
Link: http://lkml.kernel.org/r/1407996100-6359-2-git-send-email-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>