mtd: oxnas_nand: Allocating more than necessary in probe()

We only need to allocate sizeof(struct oxnas_nand_ctrl) which is 192
bytes and not sizeof(struct nand_chip) which is a much larger 3056
bytes.

Fixes: 66859249 ("mtd: nand: Add OX820 NAND Support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/oxnas_nand.c

@@ -91,7 +91,7 @@ static int oxnas_nand_probe(struct platform_device *pdev)
 	int err = 0;
 
 	/* Allocate memory for the device structure (and zero it) */
-	oxnas = devm_kzalloc(&pdev->dev, sizeof(struct nand_chip),
+	oxnas = devm_kzalloc(&pdev->dev, sizeof(*oxnas),
 			     GFP_KERNEL);
 	if (!oxnas)
 		return -ENOMEM;