driver core: don't fail attaching the device if it cannot be bound

Don't fail bus_attach_device() if the device cannot be bound.

If dev->driver has been specified, reset it to NULL if device_bind_driver()
failed and add the device as an unbound device.  As a result,
bus_attach_device() now cannot fail, and we can remove some checking from
device_add().

Also remove an unneeded check in bus_rescan_devices_helper().

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/base/core.c b/drivers/base/core.c
index bffb69e..be6aeb4 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -677,8 +677,7 @@
 		goto BusError;
 	if (!dev->uevent_suppress)
 		kobject_uevent(&dev->kobj, KOBJ_ADD);
-	if ((error = bus_attach_device(dev)))
-		goto AttachError;
+	bus_attach_device(dev);
 	if (parent)
 		klist_add_tail(&dev->knode_parent, &parent->klist_children);
 
@@ -697,8 +696,6 @@
 	kfree(class_name);
 	put_device(dev);
 	return error;
- AttachError:
-	bus_remove_device(dev);
  BusError:
 	device_pm_remove(dev);
  PMError: