x86/vsmp: Fix linker error when CONFIG_PROC_FS is not set

set_vsmp_pv_ops() references no_irq_affinity which is undeclared
if CONFIG_PROC_FS isn't set. Fix this by adding an #ifdef around
this variable's access.

Reported-by: Fengguang Wu <wfg@linux.intel.com>
Signed-off-by: Ido Yariv <ido@wizery.com>
Acked-by: Shai Fultheim <shai@scalemp.com>
Link: http://lkml.kernel.org/r/1339688588-12674-1-git-send-email-ido@wizery.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/vsmp_64.c

@@ -101,7 +101,10 @@ static void __init set_vsmp_pv_ops(void)
 #ifdef CONFIG_SMP
 	if (cap & ctl & BIT(8)) {
 		ctl &= ~BIT(8);
+#ifdef CONFIG_PROC_FS
+		/* Don't let users change irq affinity via procfs */
 		no_irq_affinity = 1;
+#endif
 	}
 #endif