cpumask: update setup_node_to_cpumask_map() comments

node_to_cpumask() has been replaced by cpumask_of_node(), and wholly
removed since commit 29c337a0 ("cpumask: remove obsolete node_to_cpumask
now everyone uses cpumask_of_node").

So update the comments for setup_node_to_cpumask_map().

Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index 4ff3d8e..3feefc3 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -58,7 +58,7 @@
  * Allocate node_to_cpumask_map based on number of available nodes
  * Requires node_possible_map to be valid.
  *
- * Note: node_to_cpumask() is not valid until after this is done.
+ * Note: cpumask_of_node() is not valid until after this is done.
  */
 static void __init setup_node_to_cpumask_map(void)
 {