purge-cluster: clean some code

Avoid using regexp to match device

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

infrastructure-playbooks/purge-cluster.yml

@@ -310,13 +310,13 @@
 
   - name: get ceph data partitions
     shell: |
-      blkid | awk -F: '/ceph data/ { print $1 }'
+      blkid -o device -t PARTLABEL="ceph data"
     failed_when: false
     register: ceph_data_partition_to_erase_path
 
   - name: get ceph lockbox partitions
     shell: |
-      blkid | awk '/ceph lockbox/ { sub (":", "", $1); print $1 }'
+      blkid -o device -t PARTLABEL="ceph lockbox"
     failed_when: false
     register: ceph_lockbox_partition_to_erase_path
 
@@ -340,25 +340,25 @@
 
   - name: get ceph block partitions
     shell: |
-      blkid | awk '/ceph block"/ { sub (":", "", $1); print $1 }'
+      blkid -o device -t PARTLABEL="ceph block"
     failed_when: false
     register: ceph_block_partition_to_erase_path
 
   - name: get ceph journal partitions
     shell: |
-      blkid | awk '/ceph journal/ { sub (":", "", $1); print $1 }'
+      blkid -o device -t PARTLABEL="ceph journal"
     failed_when: false
     register: ceph_journal_partition_to_erase_path
 
   - name: get ceph db partitions
     shell: |
-      blkid | awk '/ceph block.db/ { sub (":", "", $1); print $1 }'
+      blkid -o device -t PARTLABEL="ceph block.db"
     failed_when: false
     register: ceph_db_partition_to_erase_path
 
   - name: get ceph wal partitions
     shell: |
-      blkid | awk '/ceph block.wal/ { sub (":", "", $1); print $1 }'
+      blkid -o device -t PARTLABEL="ceph block.wal"
     failed_when: false
     register: ceph_wal_partition_to_erase_path