mm/FRV: 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.

Also fix a bug that totalhigh_pages should be increased when freeing
a highmem page into the buddy system.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/frv/mm/init.c

@@ -131,10 +131,8 @@ void __init mem_init(void)
 			datapages++;
 
 #ifdef CONFIG_HIGHMEM
-	for (pfn = num_physpages - 1; pfn >= num_mappedpages; pfn--) {
-		__free_reserved_page(&mem_map[pfn]);
-		totalram_pages++;
-	}
+	for (pfn = num_physpages - 1; pfn >= num_mappedpages; pfn--)
+		free_highmem_page(&mem_map[pfn]);
 #endif
 
 	codek = ((unsigned long) &_etext - (unsigned long) &_stext) >> 10;