s390/cio/chp: cleanup attribute usage

Let the driver core handle device attribute creation and removal. This
will simplify the code and eliminates races between attribute
availability and userspace notification via uevents.

Signed-off-by: Sebastian Ott <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

drivers/s390/cio/chp.c

···
 	&dev_attr_shared.attr,
 	NULL,
 };
-
 static struct attribute_group chp_attr_group = {
 	.attrs = chp_attrs,
+};
+static const struct attribute_group *chp_attr_groups[] = {
+	&chp_attr_group,
+	NULL,
 };
 
 static void chp_release(struct device *dev)
···
 	chp->chpid = chpid;
 	chp->state = 1;
 	chp->dev.parent = &channel_subsystems[chpid.cssid]->device;
+	chp->dev.groups = chp_attr_groups;
 	chp->dev.release = chp_release;
 	mutex_init(&chp->lock);
 
···
 		put_device(&chp->dev);
 		goto out;
 	}
-	ret = sysfs_create_group(&chp->dev.kobj, &chp_attr_group);
-	if (ret) {
-		device_unregister(&chp->dev);
-		goto out;
-	}
 	mutex_lock(&channel_subsystems[chpid.cssid]->mutex);
 	if (channel_subsystems[chpid.cssid]->cm_enabled) {
 		ret = chp_add_cmg_attr(chp);
 		if (ret) {
-			sysfs_remove_group(&chp->dev.kobj, &chp_attr_group);
 			device_unregister(&chp->dev);
 			mutex_unlock(&channel_subsystems[chpid.cssid]->mutex);
 			goto out;