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/powerpc/perf/core-book3s.c

@@ -2189,7 +2189,7 @@ int register_power_pmu(struct power_pmu *pmu)
 #endif /* CONFIG_PPC64 */
 
 	perf_pmu_register(&power_pmu, "cpu", PERF_TYPE_RAW);
-	cpuhp_setup_state(CPUHP_PERF_POWER, "PERF_POWER",
+	cpuhp_setup_state(CPUHP_PERF_POWER, "perf/powerpc:prepare",
 			  power_pmu_prepare_cpu, NULL);
 	return 0;
 }