ceph crush osd set does not create a device if it does not exist

Change "ceph crush osd set" to "ceph crush osd add" since set does
not create the device anymore (Ceph Emperor release notes)
It will add the device if it is not already there. Otherwise same
behaviour as before (set on each puppet run)
Merge branch 'fix_osd_crush' of github.com:dmsimard/puppet-ceph into mds-osd-fix