x86: fix arch/x86/kernel/genx2apic_uv_x.c build warning when !CONFIG_HOTPLUG_CPU

Impact: cleanup, reduce size of the kernel image a bit

Fix:

  arch/x86/kernel/genx2apic_uv_x.c:403: warning: 'uv_heartbeat_disable' defined but not used

the function is only used when CONFIG_HOTPLUG_CPU is defined.
Signed-off-by: NRichard A. Holden III <aciddeath@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/genx2apic_uv_x.c

@@ -400,6 +400,7 @@ static void __cpuinit uv_heartbeat_enable(int cpu)
 		uv_heartbeat_enable(0);
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
 static void __cpuinit uv_heartbeat_disable(int cpu)
 {
 	if (uv_cpu_hub_info(cpu)->scir.enabled) {
@@ -409,7 +410,6 @@ static void __cpuinit uv_heartbeat_disable(int cpu)
 	uv_set_cpu_scir_bits(cpu, 0xff);
 }
 
-#ifdef CONFIG_HOTPLUG_CPU
 /*
  * cpu hotplug notifier
  */