Upgrade fails when having cinder_qos_specs defined

[Marcus Murwall]

If you run the os-cinder-install playbook and have specified cinder_qos_specs the playbook will fail if the qos already exist in the system.

The error occurs here:
https://github.com/openstack/openstack-ansible-os_cinder/blob/f1b2eed3eb89f19acf543782c621edb6715ad6d5/tasks/cinder_qos.yml#L20

Here it does a: `{{ cinder_bin }}/cinder qos-list | grep -x {{ item.name }}`

grep definition:
 `-x, --line-regexp force PATTERN to match only whole lines`

The output from cinder qos-list will be something like:
```+--------------------------------------+------------------+-----------+-----------------------------+
| ID | Name | Consumer | specs |
+--------------------------------------+------------------+-----------+-----------------------------+
| 1a12340d-36af-48bf-9d36-b556bc252123 | my-qos-name | front-end | {'total_iops_sec': '40000'} |
+--------------------------------------+------------------+-----------+-----------------------------+```

item.name in the task will match the qos.name defined in this case:`my-qos-name`.

Since the "grep -x" matches the entire line it won't get any “hit”, which will make ansible try and create the qos again and that results in a failure on duplicate name.

If we do a `grep -w {{item_name}}` instead it will do a word match, which will work in this specific case.
Or, since we already know the name of the qos, we could just as well just do a cinder `qos-show <name>`, register that and base further execution based on if it exists or not.

[Jesse Pretorius (jesse-pretorius)]

Related patch: https://review.openstack.org/#/c/561218/