x86: use APIC_INTEGRATED tests in x86_64

This patch does not change the behaviour of x86_64, since APIC_INTEGRATED
is always defined as (1). But the code now matches exactly i386 version
(well, this part of the code, at least)
Signed-off-by: NGlauber Costa <gcosta@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/smpboot_64.c

@@ -295,6 +295,15 @@ static int __cpuinit wakeup_secondary_via_INIT(int phys_apicid, unsigned int sta
 	unsigned long send_status, accept_status = 0;
 	int maxlvt, num_starts, j;
 
+	/*
+	 * Be paranoid about clearing APIC errors.
+	 */
+	if (APIC_INTEGRATED(apic_version[phys_apicid])) {
+		apic_read_around(APIC_SPIV);
+		apic_write(APIC_ESR, 0);
+		apic_read(APIC_ESR);
+	}
+
 	Dprintk("Asserting INIT.\n");
 
 	/*
@@ -327,7 +336,10 @@ static int __cpuinit wakeup_secondary_via_INIT(int phys_apicid, unsigned int sta
 	mb();
 	atomic_set(&init_deasserted, 1);
 
-	num_starts = 2;
+	if (APIC_INTEGRATED(apic_version[phys_apicid]))
+		num_starts = 2;
+	else
+		num_starts = 0;
 
 	/*
 	 * Paravirt / VMI wants a startup IPI hook here to set up the