x86: make dev_to_node return online node

a numa system (with multi HT chains) may return node without ram. Aka it
is not online. Try to get an online node, otherwise return -1.

Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index d95de2f..ea8685f 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -172,6 +172,9 @@
 		set_mp_bus_to_node(busnum, node);
 	else
 		node = get_mp_bus_to_node(busnum);
+
+	if (node != -1 && !node_online(node))
+		node = -1;
 #endif
 
 	/* Allocate per-root-bus (not per bus) arch-specific data.