x86_64: not set boot cpu in cpu_online_map at smp_prepare_boot_cpu

Index: linux-2.6/arch/x86/kernel/smpboot_64.c
===================================================================
@@ -921,7 +921,7 @@ void __init smp_prepare_cpus(unsigned in
 void __init smp_prepare_boot_cpu(void)
 {
 	int me = smp_processor_id();
-	cpu_set(me, cpu_online_map);
+	/* already set me in cpu_online_map in boot_cpu_init() */
 	cpu_set(me, cpu_callout_map);
 	per_cpu(cpu_state, me) = CPU_ONLINE;
 }