x86/apic: Use lapic_is_integrated() consistently

lapic_is_integrated() is a wrapper around APIC_INTEGRATED(), but not used
consistently.

Replace the direct usage of APIC_INTEGRATED() and fixup a hard to read tail
comment. No functional change.

[ tglx: Made it compile and work .... ]
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1504774161-7137-2-git-send-email-douly.fnst@cn.fujitsu.com

arch/x86/kernel/apic/apic.c

@@ -294,14 +294,11 @@ int get_physical_broadcast(void)
  */
 int lapic_get_maxlvt(void)
 {
-	unsigned int v;
-
-	v = apic_read(APIC_LVR);
 	/*
 	 * - we always have APIC integrated on 64bit mode
 	 * - 82489DXs do not report # of LVT entries
 	 */
-	return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
+	return lapic_is_integrated() ? GET_APIC_MAXLVT(apic_read(APIC_LVR)) : 2;
 }
 
 /*
@@ -1531,7 +1528,9 @@ void setup_local_APIC(void)
 		value = APIC_DM_NMI;
 	else
 		value = APIC_DM_NMI | APIC_LVT_MASKED;
-	if (!lapic_is_integrated())		/* 82489DX */
+
+	/* Is 82489DX ? */
+	if (!lapic_is_integrated())
 		value |= APIC_LVT_LEVEL_TRIGGER;
 	apic_write(APIC_LVT1, value);