mtd: nand: Fix memory allocation in nanddev_bbt_init()

Fix the size of the buffer allocated to store the in-memory BBT.
This bug was previously hidden by a different bug, that was fixed in
commit d098093ba0 ("mtd: nand: Fix nanddev_neraseblocks()").

Fixes: 9c3736a3de ("mtd: nand: Add core infrastructure to deal with NAND devices")
Cc: <stable@vger.kernel.org>
Signed-off-by: Frieder Schrempf <frieder.schrempf@kontron.de>
Acked-by: Miquel Raynal <miquel.raynal@bootlin.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>

drivers/mtd/nand/bbt.c

@@ -27,7 +27,8 @@ int nanddev_bbt_init(struct nand_device *nand)
 	unsigned int nwords = DIV_ROUND_UP(nblocks * bits_per_block,
 					   BITS_PER_LONG);
 
-	nand->bbt.cache = kzalloc(nwords, GFP_KERNEL);
+	nand->bbt.cache = kcalloc(nwords, sizeof(*nand->bbt.cache),
+				  GFP_KERNEL);
 	if (!nand->bbt.cache)
 		return -ENOMEM;