mon/OSDMonitor : Use user provided ruleset for replicated pool

When creating a replicated pool, currently ceph ignore the ruleset
name provided by user but use a global default ruleset.

This patch fix this bug, so the rulset specified by
ceph osd pool create replicated
can be properly set.

Signed-off-by: Xiaoxi Chen <xiaoxi.chen@intel.com>
Merge pull request #2138 from xiaoxichen/fix_crush_ruleset

mon/OSDMonitor : Use user provided ruleset for replicated pool

Reviewed-by: Loic Dachary <loic-201408@dachary.org>