ceph-daemon: clean up dir helpers, tighten up permissions

ceph-daemon: clean up dir helpers, tighten up permissions

- don't pass args.{data,log}_dir to get_{data,log}_dir
- pass uid, gid, and mode to makedirs
- add make_data_dir and make_log_dir helpers, that optionally take uid/gid
- add make_data_dir_base that requires uid/gid
- use standard data and log dir modes, defined at top of file (0o700 for
  data, 0o770 for logs).  The data dir mode applies both to the fsid
  directory for the whole cluster and to each daemon's subdirectory; the
  log mode applies only to the fsid dir for the whole cluster, where
  all daemon logs are combined together in one directory.

Signed-off-by: Sage Weil <sage@redhat.com>