remove "struct subsystem" as it is no longer needed

We need to work on cleaning up the relationship between kobjects, ksets and
ktypes.  The removal of 'struct subsystem' is the first step of this,
especially as it is not really needed at all.

Thanks to Kay for fixing the bugs in this patch.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/kernel/power/power.h b/kernel/power/power.h
index eb461b8..5f842c3 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -35,7 +35,7 @@
 	.store	= _name##_store,		\
 }
 
-extern struct subsystem power_subsys;
+extern struct kset power_subsys;
 
 /* References to section boundaries */
 extern const void __nosave_begin, __nosave_end;