x86, smp: remove ->restore_NMI_vector()

Nothing actually restores the NMI vector - so remove this
logic altogether.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/include/asm/genapic.h

@@ -82,7 +82,6 @@ struct genapic {
 	void (*wait_for_init_deassert)(atomic_t *deassert);
 	void (*smp_callin_clear_local_apic)(void);
 	void (*store_NMI_vector)(unsigned short *high, unsigned short *low);
-	void (*restore_NMI_vector)(unsigned short *high, unsigned short *low);
 	void (*inquire_remote_apic)(int apicid);
 };