Refactor ErasureCodeLrc::create_ruleset

Refactor ErasureCodeLrc::create_ruleset
1.Use CrushWrapper instead of crush C-api.
2.Make ruleset_id == rule_id, consist as the behavior in
  CrushWrapper::add_simple_ruleset().

Signed-off-by: Xiaoxi Chen <xiaoxi.chen@intel.com>
Merge pull request #2398 from xiaoxichen/refactor_lrc_crush

Refactor ErasureCodeLrc::create_ruleset

Reviewed-by: Loic Dachary <loic@dachary.org>