Explictly set the ipa undrecloud hostname

The role relies on ansible_fqdn:
https://github.com/freeipa/ansible-freeipa/blob/master/roles/ipaclient/tasks/install.yml#L39

This does not always return the hostname required in the IPA
setup. This review passes the hostname to the playbook
so it does not default to ansible_fqdn.

Change-Id: I7318f43117c9b8dd6456dc9cc09b9b205fd8a966

roles/ipa-multinode/tasks/ipaserver-undercloud-setup.yml

@@ -92,6 +92,7 @@
   shell: >
     ansible-playbook -vvv
     --ssh-extra-args "-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null"
+    -e ipaclient_hostname="{{ undercloud_hostname }}"
     /usr/share/ansible/tripleo-playbooks/undercloud-ipa-install.yaml
     | tee undercloud-ipa-install.log
   environment: