xen/xenbus: clean up error handling

Don't report errors when booting on non-Xen, because its just confusing.
Signed-off-by: NJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: NIan Campbell <ian.campbell@citrix.com>
[corresponds to 8aa08376d6aa in git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen.git]
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/xen/xenbus/xenbus_probe.c

@@ -242,7 +242,7 @@ int xenbus_dev_probe(struct device *_dev)
 fail:
 	xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename);
 	xenbus_switch_state(dev, XenbusStateClosed);
-	return -ENODEV;
+	return err;
 }
 EXPORT_SYMBOL_GPL(xenbus_dev_probe);
 
@@ -709,7 +709,7 @@ static int __init xenbus_init(void)
 
 	err = -ENODEV;
 	if (!xen_domain())
-		goto out_error;
+		return err;
 
 	/*
 	 * Domain0 doesn't have a store_evtchn or store_mfn yet.