x86: cpu/common*.c, merge switch_to_new_gdt()

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index f44678d..43d5287 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -215,7 +215,9 @@
 	gdt_descr.address = (long)get_cpu_gdt_table(smp_processor_id());
 	gdt_descr.size = GDT_SIZE - 1;
 	load_gdt(&gdt_descr);
+#ifdef CONFIG_X86_32
 	asm("mov %0, %%fs" : : "r" (__KERNEL_PERCPU) : "memory");
+#endif
 }
 
 static struct cpu_dev *cpu_devs[X86_VENDOR_NUM] = {};