x86: move state update out of ipi_lock

it does not need to be inside lock. Do the way i386 does.
Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/smpboot_64.c

@@ -233,10 +233,10 @@ void __cpuinit start_secondary(void)
 	 */
 	spin_unlock(&vector_lock);
 	cpu_set(smp_processor_id(), cpu_online_map);
-	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
-
 	unlock_ipi_call_lock();
 
+	per_cpu(cpu_state, smp_processor_id()) = CPU_ONLINE;
+
 	setup_secondary_clock();
 
 	cpu_idle();