[IA64] remove dead code: __cpu_{down,die} from !HOTPLUG_CPU

Neither __cpu_down() nor __cpu_die() are being referenced without
CONFIG_HOTPLUG_CPU.

Signed-off-by: Jan Beulich <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Tony Luck <[e-mail]>

arch/ia64/kernel/smpboot.c

···
 	}
  	printk(KERN_ERR "CPU %u didn't die...\n", cpu);
 }
-#else /* !CONFIG_HOTPLUG_CPU */
-int __cpu_disable(void)
-{
-	return -ENOSYS;
-}
-
-void __cpu_die(unsigned int cpu)
-{
-	/* We said "no" in __cpu_disable */
-	BUG();
-}
 #endif /* CONFIG_HOTPLUG_CPU */
 
 void