cpumask: remove obsolete node_to_cpumask now everyone uses cpumask_of_node

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/arch/mips/sgi-ip27/ip27-memory.c b/arch/mips/sgi-ip27/ip27-memory.c
index 060d853d7..f61c164 100644
--- a/arch/mips/sgi-ip27/ip27-memory.c
+++ b/arch/mips/sgi-ip27/ip27-memory.c
@@ -421,7 +421,7 @@
 
 /*
  * A node with nothing.  We use it to avoid any special casing in
- * node_to_cpumask
+ * cpumask_of_node
  */
 static struct node_data null_node = {
 	.hub = {