mm: drop unneeded pgdat argument from free_area_init_node()

free_area_init_node() gets passed in the node id as well as the node
descriptor.  This is redundant as the function can trivially get the node
descriptor itself by means of NODE_DATA() and the node's id.

I checked all the users and NODE_DATA() seems to be usable everywhere
from where this function is called.

Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 833f854..6e26adc 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -455,7 +455,7 @@
 	/* we can use NODE_DATA(nid) from here */
 
 	/* init node's zones as empty zones, we don't have any present pages.*/
-	free_area_init_node(nid, pgdat, zones_size, start_pfn, zholes_size);
+	free_area_init_node(nid, zones_size, start_pfn, zholes_size);
 
 	return pgdat;
 }
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 24aa3d1..e43aae1 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3461,10 +3461,11 @@
 #endif /* CONFIG_FLAT_NODE_MEM_MAP */
 }
 
-void __paginginit free_area_init_node(int nid, struct pglist_data *pgdat,
-		unsigned long *zones_size, unsigned long node_start_pfn,
-		unsigned long *zholes_size)
+void __paginginit free_area_init_node(int nid, unsigned long *zones_size,
+		unsigned long node_start_pfn, unsigned long *zholes_size)
 {
+	pg_data_t *pgdat = NODE_DATA(nid);
+
 	pgdat->node_id = nid;
 	pgdat->node_start_pfn = node_start_pfn;
 	calculate_node_totalpages(pgdat, zones_size, zholes_size);
@@ -3961,7 +3962,7 @@
 	setup_nr_node_ids();
 	for_each_online_node(nid) {
 		pg_data_t *pgdat = NODE_DATA(nid);
-		free_area_init_node(nid, pgdat, NULL,
+		free_area_init_node(nid, NULL,
 				find_min_pfn_for_node(nid), NULL);
 
 		/* Any memory on that node */
@@ -4032,7 +4033,7 @@
 
 void __init free_area_init(unsigned long *zones_size)
 {
-	free_area_init_node(0, NODE_DATA(0), zones_size,
+	free_area_init_node(0, zones_size,
 			__pa(PAGE_OFFSET) >> PAGE_SHIFT, NULL);
 }