dm kcopyd: return client directly and not through a pointer

Return client directly from dm_kcopyd_client_create, not through a
parameter, making it consistent with dm_io_client_create.

Signed-off-by: Mikulas Patocka <[e-mail]>
Signed-off-by: Alasdair G Kergon <[e-mail]>

drivers/md/dm-kcopyd.c

···
 /*-----------------------------------------------------------------
  * Client setup
  *---------------------------------------------------------------*/
-int dm_kcopyd_client_create(struct dm_kcopyd_client **result)
+struct dm_kcopyd_client *dm_kcopyd_client_create(void)
 {
 	int r = -ENOMEM;
 	struct dm_kcopyd_client *kc;
 
 	kc = kmalloc(sizeof(*kc), GFP_KERNEL);
 	if (!kc)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
 
 	spin_lock_init(&kc->job_lock);
 	INIT_LIST_HEAD(&kc->complete_jobs);
···
 	init_waitqueue_head(&kc->destroyq);
 	atomic_set(&kc->nr_jobs, 0);
 
-	*result = kc;
-	return 0;
+	return kc;
 
 bad_io_client:
 	client_free_pages(kc);
···
 bad_slab:
 	kfree(kc);
 
-	return r;
+	return ERR_PTR(r);
 }
 EXPORT_SYMBOL(dm_kcopyd_client_create);
 

drivers/md/dm-raid1.c

···
 		goto err_destroy_wq;
 	}
 
-	r = dm_kcopyd_client_create(&ms->kcopyd_client);
-	if (r)
+	ms->kcopyd_client = dm_kcopyd_client_create();
+	if (IS_ERR(ms->kcopyd_client)) {
+		r = PTR_ERR(ms->kcopyd_client);
 		goto err_destroy_wq;
+	}
 
 	wakeup_mirrord(ms);
 	return 0;

drivers/md/dm-snap.c

···
 		goto bad_hash_tables;
 	}
 
-	r = dm_kcopyd_client_create(&s->kcopyd_client);
-	if (r) {
+	s->kcopyd_client = dm_kcopyd_client_create();
+	if (IS_ERR(s->kcopyd_client)) {
+		r = PTR_ERR(s->kcopyd_client);
 		ti->error = "Could not create kcopyd client";
 		goto bad_kcopyd;
 	}

include/linux/dm-kcopyd.h

···
  * To use kcopyd you must first create a dm_kcopyd_client object.
  */
 struct dm_kcopyd_client;
-int dm_kcopyd_client_create(struct dm_kcopyd_client **result);
+struct dm_kcopyd_client *dm_kcopyd_client_create(void);
 void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc);
 
 /*