drivers: rkflash: Fixed bbt operation calculation error

Fixes: 008340a82 ("drivers: rkflash: Change to use the api which the oob area available")
Change-Id: I140aa76a2acb73271ba04b7060030dc06a2353e6
Signed-off-by: Jon Lin <jon.lin@rock-chips.com>

Author: Jon Lin

drivers/rkflash/sfc_nand_mtd_bbt.c

@@ -166,7 +166,7 @@ static int nanddev_write_bbt(struct snand_mtd_dev *nand, u32 block)
 	bbt_info->version = nand->bbt.version;
 
 	/* Store one entry for each block */
-	ret = sfc_nand_erase_mtd(mtd, block / mtd->erasesize);
+	ret = sfc_nand_erase_mtd(mtd, block * mtd->erasesize);
 	if (ret)
 		goto out;