Don't try to set devices fact when osd_auto_discovery was skipped

Don't try to set devices fact when osd_auto_discovery was skipped

Right now, under certain OS and Ansible versions, ie Rocky Linux and
ansible-core 2.17, `devices_check` variable is getting defined even if
task was skipped.

That results in set_fact to fail, as resulting variable has no `results`
key in it.

Structure of such variable looks like that:
```
"devices_check": {
    "changed": false,
    "false_condition": "osd_auto_discovery | default(False) | bool",
    "skip_reason": "Conditional result was False",
    "skipped": true
}
```

Checking for task not being skipped solves such issues.

Signed-off-by: Dmitriy Rabotyagov <noonedeadpunk@gmail.com>
(cherry picked from commit 9405558d03b633f8677d0f5f559028ca61ea4403)