drivers/video/acornfb.c: use __free_reserved_page() to simplify the code

Use __free_reserved_page() to simplify the code in the others.
Signed-off-by: NXishi Qiu <qiuxishi@huawei.com>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

drivers/video/acornfb.c

@@ -949,9 +949,7 @@ free_unused_pages(unsigned int virtual_start, unsigned int virtual_end)
 		 * the page.
 		 */
 		page = virt_to_page(virtual_start);
-		ClearPageReserved(page);
-		init_page_count(page);
-		free_page(virtual_start);
+		__free_reserved_page(page);
 
 		virtual_start += PAGE_SIZE;
 		mb_freed += PAGE_SIZE / 1024;