Set init_system fact and reference in ceph-osd role
Set init_system fact and reference in ceph-osd role

The ceph-osd role currently uses ansible_service_mgr, which is a fact
only available on ansible 2.x and greater.  This commit sets a similar
fact called init_system which will store the contents of /proc/1/comm
(systemd, init, etc.) and then references it ceph-osd instead.

Closes #741

ceph/ansible-ceph-common