[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/cpuid.c

@@ -167,7 +167,6 @@ static int cpuid_device_create(int i)
 	return err;
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
 static int cpuid_class_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
 {
 	unsigned int cpu = (unsigned long)hcpu;
@@ -187,7 +186,6 @@ static struct notifier_block __cpuinitdata cpuid_class_cpu_notifier =
 {
 	.notifier_call = cpuid_class_cpu_callback,
 };
-#endif /* !CONFIG_HOTPLUG_CPU */
 
 static int __init cpuid_init(void)
 {