mm/metag: use free_highmem_page() to free highmem pages into buddy system

Use helper function free_highmem_page() to free highmem pages into
the buddy system.
Signed-off-by: NJiang Liu <jiang.liu@huawei.com>
Cc: James Hogan <james.hogan@imgtec.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/metag/mm/init.c

@@ -380,14 +380,8 @@ void __init mem_init(void)
 
 #ifdef CONFIG_HIGHMEM
 	unsigned long tmp;
-	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
-		struct page *page = pfn_to_page(tmp);
-		ClearPageReserved(page);
-		init_page_count(page);
-		__free_page(page);
-		totalhigh_pages++;
-	}
-	totalram_pages += totalhigh_pages;
+	for (tmp = highstart_pfn; tmp < highend_pfn; tmp++)
+		free_highmem_page(pfn_to_page(tmp));
 	num_physpages += totalhigh_pages;
 #endif /* CONFIG_HIGHMEM */