x86/ioapic: Return suitable error code in mp_map_gsi_to_irq()

mp_map_gsi_to_irq() in some cases might return legacy -1, which would be
wrongly interpreted as -EPERM.

Correct those cases to return proper error code.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: http://lkml.kernel.org/r/20170119192425.189899-2-andriy.shevchenko@linux.intel.comSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/apic/io_apic.c

@@ -1107,12 +1107,12 @@ int mp_map_gsi_to_irq(u32 gsi, unsigned int flags, struct irq_alloc_info *info)
 
 	ioapic = mp_find_ioapic(gsi);
 	if (ioapic < 0)
-		return -1;
+		return -ENODEV;
 
 	pin = mp_find_ioapic_pin(ioapic, gsi);
 	idx = find_irq_entry(ioapic, pin, mp_INT);
 	if ((flags & IOAPIC_MAP_CHECK) && idx < 0)
-		return -1;
+		return -ENODEV;
 
 	return mp_map_pin_to_irq(gsi, idx, ioapic, pin, flags, info);
 }