mm, slab: moved kmem_cache_alloc_node comment to correct place

After several fixing about kmem_cache_alloc_node(), its comment
was splitted. This patch moved it on top of kmem_cache_alloc_node()
definition.
Signed-off-by: NZhouping Liu <zliu@redhat.com>
Signed-off-by: NPekka Enberg <penberg@kernel.org>

mm/slab.c

@@ -3340,18 +3340,6 @@ static void *____cache_alloc_node(struct kmem_cache *cachep, gfp_t flags,
 	return obj;
 }
 
-/**
- * kmem_cache_alloc_node - Allocate an object on the specified node
- * @cachep: The cache to allocate from.
- * @flags: See kmalloc().
- * @nodeid: node number of the target node.
- * @caller: return address of caller, used for debug information
- *
- * Identical to kmem_cache_alloc but it will allocate memory on the given
- * node, which can improve the performance for cpu bound structures.
- *
- * Fallback to other node is possible if __GFP_THISNODE is not set.
- */
 static __always_inline void *
 slab_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid,
 		   unsigned long caller)
@@ -3645,6 +3633,17 @@ EXPORT_SYMBOL(kmem_cache_alloc_trace);
 #endif
 
 #ifdef CONFIG_NUMA
+/**
+ * kmem_cache_alloc_node - Allocate an object on the specified node
+ * @cachep: The cache to allocate from.
+ * @flags: See kmalloc().
+ * @nodeid: node number of the target node.
+ *
+ * Identical to kmem_cache_alloc but it will allocate memory on the given
+ * node, which can improve the performance for cpu bound structures.
+ *
+ * Fallback to other node is possible if __GFP_THISNODE is not set.
+ */
 void *kmem_cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid)
 {
 	void *ret = slab_alloc_node(cachep, flags, nodeid, _RET_IP_);