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/xtensa/kernel/perf_event.c

@@ -422,7 +422,7 @@ static int __init xtensa_pmu_init(void)
 	int irq = irq_create_mapping(NULL, XCHAL_PROFILING_INTERRUPT);
 
 	ret = cpuhp_setup_state(CPUHP_AP_PERF_XTENSA_STARTING,
-				"AP_PERF_XTENSA_STARTING", xtensa_pmu_setup,
+				"perf/xtensa:starting", xtensa_pmu_setup,
 				NULL);
 	if (ret) {
 		pr_err("xtensa_pmu: failed to register CPU-hotplug.\n");