locking: fix mutex @key parameter kernel-doc notation

Fix @key parameter to mutex_init() and one of its callers.

Warning(linux-2.6.26-git11//drivers/base/class.c:210): No description found for parameter 'key'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/base/class.c b/drivers/base/class.c
index 839d27c..5667c2f 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -198,6 +198,7 @@
  * class_create - create a struct class structure
  * @owner: pointer to the module that is to "own" this struct class
  * @name: pointer to a string for the name of this class.
+ * @key: the lock_class_key for this class; used by mutex lock debugging
  *
  * This is used to create a struct class pointer that can then be used
  * in calls to device_create().