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 <pg_num> <pgp_num> replicated <my_ruleset_name>
can be properly set.

Signed-off-by: Xiaoxi Chen <xiaoxi.chen@intel.com>
There is no convenient way to fix this. Instead, the argument could be renamed in https://github.com/ceph/ceph/blob/master/src/mon/MonCommands.h#L554 to reflect the fact that it depends on the context (for instance profile_or_ruleset ) ?