kobject core: remove rwsem from struct subsystem

It isn't used at all by the driver core anymore, and the few usages of
it within the kernel have now all been fixed as most of them were using
it incorrectly.  So remove it.

Now the whole struct subsys can be removed from the system, but that's
for a later patch...

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

include/linux/kobject.h

@@ -22,7 +22,6 @@
 #include <linux/sysfs.h>
 #include <linux/compiler.h>
 #include <linux/spinlock.h>
-#include <linux/rwsem.h>
 #include <linux/kref.h>
 #include <linux/kernel.h>
 #include <linux/wait.h>
@@ -177,7 +176,6 @@ extern struct kobject * kset_find_obj(struct kset *, const char *);
 
 struct subsystem {
 	struct kset		kset;
-	struct rw_semaphore	rwsem;
 };
 
 #define decl_subsys(_name,_type,_uevent_ops) \

lib/kobject.c

@@ -652,7 +652,6 @@ struct kobject * kset_find_obj(struct kset * kset, const char * name)
 
 void subsystem_init(struct subsystem * s)
 {
-	init_rwsem(&s->rwsem);
 	kset_init(&s->kset);
 }
 
@@ -661,8 +660,7 @@ void subsystem_init(struct subsystem * s)
  *	@s:	the subsystem we're registering.
  *
  *	Once we register the subsystem, we want to make sure that 
- *	the kset points back to this subsystem for correct usage of 
- *	the rwsem. 
+ *	the kset points back to this subsystem.
  */
 
 int subsystem_register(struct subsystem * s)