validate: prevent from installing OSD on same disk as the OS
validate: prevent from installing OSD on same disk as the OS

This commit adds a validation task to prevent from installing an OSD on
the same disk as the OS.

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1623580

Signed-off-by: Guillaume Abrioux <30a9df5a0293a6108675377fa1673f7aa713f915@redhat.com>

ceph/ceph-ansible,ceph/ceph-ansible