Lockdep: fix compile error in drivers/input/serio/serio.c

lockdep_set_subclass() was missing in !LOCKDEP case

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 14fec2a..819f08f 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -268,6 +268,8 @@
 		do { (void)(key); } while (0)
 #define lockdep_set_class_and_subclass(lock, key, sub) \
 		do { (void)(key); } while (0)
+#define lockdep_set_subclass(lock, sub)		do { } while (0)
+
 # define INIT_LOCKDEP
 # define lockdep_reset()		do { debug_locks = 1; } while (0)
 # define lockdep_free_key_range(start, size)	do { } while (0)