x86: unlock_ExtINT_logic() - fix section mismatch warnings

Fix following warning:
WARNING: arch/x86/kernel/built-in.o(.text+0x12cc9): Section mismatch in reference from the function unlock_ExtINT_logic()

unlock_ExtINT_logic() is only used by __init check_timer(). Annotate unlock_ExtINT_logic() witch __init.
Signed-off-by: NJacek Luczak <luczak.jacek@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/io_apic_32.c

@@ -2068,7 +2068,7 @@ static void __init setup_nmi(void)
  * cycles as some i82489DX-based boards have glue logic that keeps the
  * 8259A interrupt line asserted until INTA.  --macro
  */
-static inline void unlock_ExtINT_logic(void)
+static inline void __init unlock_ExtINT_logic(void)
 {
 	int apic, pin, i;
 	struct IO_APIC_route_entry entry0, entry1;