[PATCH] x86_64: oprofile build fix

WARNING: "unset_nmi_callback" [arch/x86_64/oprofile/oprofile.ko] undefined!
WARNING: "set_nmi_callback" [arch/x86_64/oprofile/oprofile.ko] undefined!

Cc: Andi Kleen <ak@muc.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

arch/x86_64/kernel/nmi.c

@@ -607,11 +607,13 @@ void set_nmi_callback(nmi_callback_t callback)
 	vmalloc_sync_all();
 	rcu_assign_pointer(nmi_callback, callback);
 }
+EXPORT_SYMBOL_GPL(set_nmi_callback);
 
 void unset_nmi_callback(void)
 {
 	nmi_callback = dummy_nmi_callback;
 }
+EXPORT_SYMBOL_GPL(unset_nmi_callback);
 
 #ifdef CONFIG_SYSCTL