purge: remove references to ceph-disk

as of stable-4.0, ceph-disk is no longer supported.
These tasks aren't needed anymore.

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

infrastructure-playbooks/purge-cluster.yml

@@ -257,11 +257,6 @@
       - reboot_osd_node
       - remove_osd_mountpoints.failed is defined
 
-  - name: see if ceph-disk is installed
-    shell: "which ceph-disk"
-    failed_when: false
-    register: ceph_disk_present
-
   - name: wipe table on dm-crypt devices
     command: dmsetup wipe_table --force "{{ item }}"
     with_items: "{{ encrypted_ceph_partuuid.stdout_lines }}"

infrastructure-playbooks/purge-docker-cluster.yml

@@ -361,6 +361,7 @@
       CEPH_CONTAINER_BINARY: "{{ container_binary }}"
     with_items: "{{ lvm_volumes }}"
     when: lvm_volumes | default([]) | length > 0
+
   - name: zap and destroy osds created by ceph-volume with devices
     ceph_volume:
       data: "{{ item }}"