nfs: stop nfs server service

The syntax here wasn't working, this refact fixes this task.
Also, removing the `ignore_errors: true` which was hidding the failure.

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1508506

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>
(cherry picked from commit 47034effe0)

roles/ceph-nfs/tasks/pre_requisite_non_container.yml

@@ -234,7 +234,7 @@
 
 - name: stop nfs server service
   systemd:
-    name: "{%- if ansible_os_family == 'RedHat' 'nfs-server' %}{%- endif %}{%- if ansible_os_family == 'Suse' 'nfsserver' %}{%- endif %}{%- if ansible_os_family == 'Debian' 'nfs-kernel-server' %}{%- endif %}"
+    name: "{{ 'nfs-server' if ansible_os_family == 'RedHat' else 'nfsserver' if ansible_os_family == 'Suse' else 'nfs-kernel-server' if ansible_os_family == 'Debian' }}"
     state: stopped
     enabled: no
-  ignore_errors: true
+  failed_when: false