[PATCH] hotplug CPU: clean up hotcpu_notifier() use

There was lots of #ifdef noise in the kernel due to hotcpu_notifier(fn,
prio) not correctly marking 'fn' as used in the !HOTPLUG_CPU case, and thus
generating compiler warnings of unused symbols, hence forcing people to add
#ifdefs.

the compiler can skip truly unused functions just fine:

    text    data     bss     dec     hex filename
 1624412  728710 3674856 6027978  5bfaca vmlinux.before
 1624412  728710 3674856 6027978  5bfaca vmlinux.after

[akpm@osdl.org: topology.c fix]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/i386/kernel/cpu/mcheck/therm_throt.c

@@ -116,7 +116,6 @@ static __cpuinit int thermal_throttle_add_dev(struct sys_device *sys_dev)
 	return sysfs_create_group(&sys_dev->kobj, &thermal_throttle_attr_group);
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
 static __cpuinit void thermal_throttle_remove_dev(struct sys_device *sys_dev)
 {
 	return sysfs_remove_group(&sys_dev->kobj, &thermal_throttle_attr_group);
@@ -153,7 +152,6 @@ static struct notifier_block thermal_throttle_cpu_notifier =
 {
 	.notifier_call = thermal_throttle_cpu_callback,
 };
-#endif /* CONFIG_HOTPLUG_CPU */
 
 static __init int thermal_throttle_init_device(void)
 {