hugetlb: factor out prep_new_huge_page

Needed to avoid code duplication in follow up patches.
Acked-by: NAdam Litke <agl@us.ibm.com>
Acked-by: NNishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NNick Piggin <npiggin@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mm/hugetlb.c

@@ -513,6 +513,16 @@ static int adjust_pool_surplus(int delta)
 	return ret;
 }
 
+static void prep_new_huge_page(struct page *page, int nid)
+{
+	set_compound_page_dtor(page, free_huge_page);
+	spin_lock(&hugetlb_lock);
+	nr_huge_pages++;
+	nr_huge_pages_node[nid]++;
+	spin_unlock(&hugetlb_lock);
+	put_page(page); /* free it into the hugepage allocator */
+}
+
 static struct page *alloc_fresh_huge_page_node(int nid)
 {
 	struct page *page;
@@ -526,12 +536,7 @@ static struct page *alloc_fresh_huge_page_node(int nid)
 			__free_pages(page, HUGETLB_PAGE_ORDER);
 			return NULL;
 		}
-		set_compound_page_dtor(page, free_huge_page);
-		spin_lock(&hugetlb_lock);
-		nr_huge_pages++;
-		nr_huge_pages_node[nid]++;
-		spin_unlock(&hugetlb_lock);
-		put_page(page); /* free it into the hugepage allocator */
+		prep_new_huge_page(page, nid);
 	}
 
 	return page;