Make the existing playbooks pass the new checks

Strip trailing whitespace and blank lines, name the getent tasks, and fix Jinja spacing.

iot/roles/grafana/tasks/main.yaml

@@ -1,6 +1,7 @@
 ---
 # Tasks for Grafana role
-- getent:
+- name: Look up the Grafana user
+  getent:
     database: passwd
     key: "{{ grafana_user }}"
     split: ":"