x86/apic: Sanitize ioapic handling

We have proper stubs for the IOAPIC=n case and the setup/enable
function have the required checks inside now. Remove the ifdeffery and
the copy&pasted conditionals.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>C
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20150115211703.569830549@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/apic/apic.c

@@ -1905,24 +1905,13 @@ int __init APIC_init_uniprocessor(void)
 	physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
 	setup_local_APIC();
 
-#ifdef CONFIG_X86_IO_APIC
-	/*
-	 * Now enable IO-APICs, actually call clear_IO_APIC
-	 * We need clear_IO_APIC before enabling error vector
-	 */
-	if (!skip_ioapic_setup && nr_ioapics)
-		enable_IO_APIC();
-#endif
+	/* Enable IO-APICs before enabling error vector */
+	enable_IO_APIC();
 
 	bsp_end_local_APIC_setup();
 
-#ifdef CONFIG_X86_IO_APIC
-	if (smp_found_config && !skip_ioapic_setup && nr_ioapics)
+	if (smp_found_config)
 		setup_IO_APIC();
-	else {
-		nr_ioapics = 0;
-	}
-#endif
 
 	x86_init.timers.setup_percpu_clockev();
 	return 0;