perf config: Rework buildid_dir_command_config to perf_buildid_config

To avoid repeated calling perf_config() remove
buildid_dir_command_config() and add new perf_buildid_config into
perf_default_config.

Because perf_config() is already called with perf_default_config at
main().

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1459099340-16911-2-git-send-email-treeze.taeung@gmail.com


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