[PATCH] ia64: fix is_headless_node() for systems w/<64p

I didn't realize that any_online_cpu() wouldn't work for
is_headless_node(), so this patch reverts the function back to using the
node_to_cpu_mask[] array, fixing sn2 for systems with less than 64p.

include/asm-ia64/sn/nodepda.h

@@ -128,7 +128,7 @@ typedef struct irqpda_s irqpda_t;
  * Check if given a compact node id the corresponding node has all the
  * cpus disabled. 
  */
-#define is_headless_node(cnode)		(!any_online_cpu(node_to_cpumask(cnode)))
+#define is_headless_node(cnode)		(!node_to_cpu_mask[cnode])
 
 /*
  * Check if given a node vertex handle the corresponding node has all the