purge-container: remove awk usage in favor of blkid
purge-container: remove awk usage in favor of blkid

Avoid using `awk` to get the different devices from the partlabel.
Using `blkid` is more readable.

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

travmi/ceph-ansible,font/ceph-ansible,fgal/ceph-ansible,travmi/ceph-ansible,font/ceph-ansible,ceph/ceph-ansible,fgal/ceph-ansible,ceph/ceph-ansible