Train only: supply the stack name when creating the inventory

The function issues only a warning, that it couldn't generate
the inventory for a non-existing deployment, later on, ansible
also only issues a warning that it can't parse the inventory.
This resulted in iterating over an empty list of hosts and
not removing the host entries from IPA.

Change-Id: I94599322eb8b77f00bd46e0100db4d7beedec536
Resolves: rhbz#1869001
Closes-Bug: #1894904

tripleoclient/v1/overcloud_delete.py

@@ -120,6 +120,7 @@ class DeleteOvercloud(command.Command):
 
         try:
             static_inventory = utils.get_tripleo_ansible_inventory(
+                stack=stack_name,
                 return_inventory_file_path=True)
         except exceptions.InvalidConfiguration:
             self.log.warning(