purge-cluster: get journal partitions after zapping osd disks

In my testing zapping the osd disks deleted the journal
partitions, making the 'zap ceph journal partitions' task fail because
the partitions it found previously do not exist anymore.

This moves the task that finds the journal partitions after 'zap osd disks'
to catch any partitions ceph-disk might have missed.

Signed-off-by: Andrew Schoen <aschoen@redhat.com>

infrastructure-playbooks/purge-cluster.yml

@@ -357,14 +357,6 @@
     failed_when: false
     register: ceph_journal_partlabels
 
-  - name: get ceph journal partitions
-    shell: |
-      blkid | awk '/ceph journal/ { sub (":", "", $1); print $1 }'
-    when:
-      - ceph_journal_partlabels.rc == 0
-    failed_when: false
-    register: ceph_journal_partition_to_erase_path
-
   - name: get osd data mount points
     shell: "(grep /var/lib/ceph/osd /proc/mounts || echo -n) | awk '{ print $2 }'"
     register: mounted_osd
@@ -408,6 +400,14 @@
      ceph_data_partlabels.rc == 0 and
      zap_block_devs
 
+  - name: get ceph journal partitions
+    shell: |
+      blkid | awk '/ceph journal/ { sub (":", "", $1); print $1 }'
+    when:
+      - ceph_journal_partlabels.rc == 0
+    failed_when: false
+    register: ceph_journal_partition_to_erase_path
+
   - name: zap ceph journal partitions
     shell: |
       # if the disk passed is a raw device AND the boot system disk