cpu/hotplug: Cleanup state names

When the state names got added a script was used to add the extra argument
to the calls. The script basically converted the state constant to a
string, but the cleanup to convert these strings into meaningful ones did
not happen.

Replace all the useless strings with 'subsys/xxx/yyy:state' strings which
are used in all the other places already.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/arm/xen/enlighten.c

@@ -412,7 +412,7 @@ static int __init xen_guest_init(void)
 		pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier);
 
 	return cpuhp_setup_state(CPUHP_AP_ARM_XEN_STARTING,
-				 "AP_ARM_XEN_STARTING", xen_starting_cpu,
+				 "arm/xen:starting", xen_starting_cpu,
 				 xen_dying_cpu);
 }
 early_initcall(xen_guest_init);