mm/memory_hotplug: use ensure_zone_is_initialized()

Remove open coding of ensure_zone_is_initialzied().
Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Hansen <dave@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memory_hotplug.c

@@ -300,12 +300,9 @@ static int __meminit move_pfn_range_left(struct zone *z1, struct zone *z2,
 	unsigned long flags;
 	unsigned long z1_start_pfn;
 
-	if (!z1->wait_table) {
-		ret = init_currently_empty_zone(z1, start_pfn,
-			end_pfn - start_pfn, MEMMAP_HOTPLUG);
-		if (ret)
-			return ret;
-	}
+	ret = ensure_zone_is_initialized(z1, start_pfn, end_pfn - start_pfn);
+	if (ret)
+		return ret;
 
 	pgdat_resize_lock(z1->zone_pgdat, &flags);
 
@@ -345,12 +342,9 @@ static int __meminit move_pfn_range_right(struct zone *z1, struct zone *z2,
 	unsigned long flags;
 	unsigned long z2_end_pfn;
 
-	if (!z2->wait_table) {
-		ret = init_currently_empty_zone(z2, start_pfn,
-			end_pfn - start_pfn, MEMMAP_HOTPLUG);
-		if (ret)
-			return ret;
-	}
+	ret = ensure_zone_is_initialized(z2, start_pfn, end_pfn - start_pfn);
+	if (ret)
+		return ret;
 
 	pgdat_resize_lock(z1->zone_pgdat, &flags);
 
@@ -403,16 +397,13 @@ static int __meminit __add_zone(struct zone *zone, unsigned long phys_start_pfn)
 	int nid = pgdat->node_id;
 	int zone_type;
 	unsigned long flags;
+	int ret;
 
 	zone_type = zone - pgdat->node_zones;
-	if (!zone->wait_table) {
-		int ret;
+	ret = ensure_zone_is_initialized(zone, phys_start_pfn, nr_pages);
+	if (ret)
+		return ret;
 
-		ret = init_currently_empty_zone(zone, phys_start_pfn,
-						nr_pages, MEMMAP_HOTPLUG);
-		if (ret)
-			return ret;
-	}
 	pgdat_resize_lock(zone->zone_pgdat, &flags);
 	grow_zone_span(zone, phys_start_pfn, phys_start_pfn + nr_pages);
 	grow_pgdat_span(zone->zone_pgdat, phys_start_pfn,