Fix check for existing nvdimm namespaces

Due to the use of a folding block operator instead of the literal block
operator the check for existing namespaces does not work correct and
namespaces get created on subsequent deploy runs even if they already
exist. Now namespaces won't get created if the are already there.

Change-Id: I7ada7a7b78b7930a68d0204e217e3640c3dd5c73
(cherry picked from commit c437eacb13)

releasenotes/notes/fix_nvdimm_ns_check-cb0837b5dbf40ab7.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Due to the use of a folding block operator instead of the literal block
+    operator the check for existing namespaces does not work correct and
+    namespaces get created on subsequent deploy runs even if they already
+    exist. Now namespaces won't get created if the are already there.

tripleo_ansible/roles/tripleo_nvdimm/tasks/create_namespaces.yml

@@ -15,15 +15,15 @@
 # under the License.
 
 - name: list current namespaces
-  shell: >-
-    ndctl list -X | jq ".[].name"
+  shell: |
+    ndctl list -X | jq -r ".[].name"
   register: namespaces
   changed_when: false
 - name: create namespace
   command: >-
     ndctl create-namespace -s {{ input[0] }} -m devdax -M mem -n {{ input[1] }}
   when:
-    - namespaces.stdout is defined
-    - input[1] not in namespaces.stdout
+    - namespaces.stdout_lines is defined
+    - input[1] not in namespaces.stdout_lines
   register: ret
   changed_when: ret.rc == 0