drivers/xen/xenbus/xenbus_client.c: cleanup kerneldoc

no argument named @xbt in xenbus_switch_state(), remove it.
Signed-off-by: NQinghuang Feng <qhfeng.kernel@gmail.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/xen/xenbus/xenbus_client.c

@@ -136,7 +136,6 @@ EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt);
 /**
  * xenbus_switch_state
  * @dev: xenbus device
- * @xbt: transaction handle
  * @state: new state
  *
  * Advertise in the store a change of the given driver to the given new_state.
@@ -267,7 +266,7 @@ EXPORT_SYMBOL_GPL(xenbus_dev_error);
  * @fmt: error message format
  *
  * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by
- * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly
+ * xenbus_switch_state(dev, XenbusStateClosing) to schedule an orderly
  * closedown of this driver and its peer.
  */