x86: Section mismatch fixes

This patch fixes section mismatch warnings in smpboot_setup_io_apic().

WARNING: arch/x86/kernel/built-in.o(.text+0x11781): Section mismatch in reference from the function smpboot_setup_io_apic() to the function .init.text:setup_IO_APIC()
The function smpboot_setup_io_apic() references
the function __init setup_IO_APIC().
This is often because smpboot_setup_io_apic lacks a __init
annotation or the annotation of setup_IO_APIC is wrong.

---
 smpboot_hooks.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index 3ff2c5b..56d0e1f 100644
@@ -33,7 +33,7 @@ static inline void smpboot_restore_warm_reset_vector(void)
 	*((volatile long *) phys_to_virt(0x467)) = 0;
 }
 
-static inline void smpboot_setup_io_apic(void)
+static inline void __init smpboot_setup_io_apic(void)
 {
 	/*
 	 * Here we can be sure that there is an IO-APIC in the system. Let's