x86/voyager: fix compile breakage caused by dc1e35c6e95e8923cf1d3510438b63c600fee1e2

Impact: build fix on x86/Voyager

Given commits like this:

| Author: Suresh Siddha <suresh.b.siddha@intel.com>
| Date:   Tue Jul 29 10:29:19 2008 -0700
|
|     x86, xsave: enable xsave/xrstor on cpus with xsave support

Which deliberately expose boot cpu dependence to pieces of the system,
I think it's time to explicitly have a variable for it to prevent this
continual misassumption that the boot CPU is zero.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.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 25581dc..93e9393 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1134,7 +1134,7 @@
 	/*
 	 * Boot processor to setup the FP and extended state context info.
 	 */
-	if (!smp_processor_id())
+	if (smp_processor_id() == boot_cpu_id)
 		init_thread_xstate();
 
 	xsave_init();