mtd: nand: sunxi: use mtd_div_by_ws() helper

Suggested-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: NBrian Norris <computersforpeace@gmail.com>
Acked-by: NBoris Brezillon <boris.brezillon@free-electrons.com>

drivers/mtd/nand/sunxi_nand.c

@@ -624,7 +624,7 @@ static u16 sunxi_nfc_randomizer_step(u16 state, int count)
 static u16 sunxi_nfc_randomizer_state(struct mtd_info *mtd, int page, bool ecc)
 {
 	const u16 *seeds = sunxi_nfc_randomizer_page_seeds;
-	int mod = mtd->erasesize / mtd->writesize;
+	int mod = mtd_div_by_ws(mtd->erasesize, mtd);
 
 	if (mod > ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds))
 		mod = ARRAY_SIZE(sunxi_nfc_randomizer_page_seeds);