x86: fix sparse warning in topology.c

arch/x86/kernel/topology.c:56:2: warning: returning void-valued expression
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/topology.c

@@ -53,7 +53,7 @@ EXPORT_SYMBOL(arch_register_cpu);
 
 void arch_unregister_cpu(int num)
 {
-	return unregister_cpu(&per_cpu(cpu_devices, num).cpu);
+	unregister_cpu(&per_cpu(cpu_devices, num).cpu);
 }
 EXPORT_SYMBOL(arch_unregister_cpu);
 #else