Fix overcloud delete command

In change I6d41f74f9271c17bcae67eb3c09460051f55667f we changed the
signature of delete_deployment_plan from:
def delete_deployment_plan(workflow_client, **input_)

to:
def delete_deployment_plan(clients, **workflow_input)

In that change we did adjust tripleoclient/v1/overcloud_plan.py
but we forgot the overcloud delete.

We need to make sure we pass the clients and not the workflow_engine
itself when we invoke the function in tripleoclient.

Tested-By: Raoul Scarazzini <rscarazz@redhat.com>

Change-Id: I88642f5d60be629de90312523a3a9c5ea1e4fd63
Closes-Bug: #1776313

tripleoclient/v1/overcloud_delete.py

@@ -66,11 +66,11 @@ class DeleteOvercloud(command.Command):
                     "Error occurred during stack delete {}".
                     format(e))
 
-    def _plan_delete(self, workflow_client, stack_name):
+    def _plan_delete(self, clients, stack_name):
         print("Deleting plan {s}...".format(s=stack_name))
         try:
             plan_management.delete_deployment_plan(
-                workflow_client,
+                clients,
                 container=stack_name)
         except Exception as err:
             raise oscexc.CommandError(
@@ -90,8 +90,7 @@ class DeleteOvercloud(command.Command):
                 raise oscexc.CommandError("Action not confirmed, exiting.")
 
         clients = self.app.client_manager
-        workflow_client = clients.workflow_engine
 
         self._stack_delete(clients, parsed_args.stack)
-        self._plan_delete(workflow_client, parsed_args.stack)
+        self._plan_delete(clients, parsed_args.stack)
         print("Success.")