[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>
diff --git a/kernel/profile.c b/kernel/profile.c
index 04fd84e..0961d93 100644
--- a/kernel/profile.c
+++ b/kernel/profile.c
@@ -319,7 +319,6 @@
 	put_cpu();
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
 static int __devinit profile_cpu_callback(struct notifier_block *info,
 					unsigned long action, void *__cpu)
 {
@@ -372,10 +371,10 @@
 	}
 	return NOTIFY_OK;
 }
-#endif /* CONFIG_HOTPLUG_CPU */
 #else /* !CONFIG_SMP */
 #define profile_flip_buffers()		do { } while (0)
 #define profile_discard_flip_buffers()	do { } while (0)
+#define profile_cpu_callback		NULL
 
 void profile_hits(int type, void *__pc, unsigned int nr_hits)
 {