slub: Reduce #ifdef ZONE_DMA by moving kmalloc_caches_dma near dma logic

Move the definition of kmalloc_caches_dma() into a later #ifdef CONFIG_ZONE_DMA.
This saves one #ifdef and leaves us with a total of two #ifdefs for dma slab support.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
diff --git a/mm/slub.c b/mm/slub.c
index 15a7a0d..3df6d5b 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2412,10 +2412,6 @@
 struct kmem_cache kmalloc_caches[PAGE_SHIFT + 1] __cacheline_aligned;
 EXPORT_SYMBOL(kmalloc_caches);
 
-#ifdef CONFIG_ZONE_DMA
-static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1];
-#endif
-
 static int __init setup_slub_min_order(char *str)
 {
 	get_option(&str, &slub_min_order);
@@ -2475,6 +2471,7 @@
 }
 
 #ifdef CONFIG_ZONE_DMA
+static struct kmem_cache *kmalloc_caches_dma[PAGE_SHIFT + 1];
 
 static void sysfs_add_func(struct work_struct *w)
 {