gen_nand: Test if nr_chips field is valid

Signed-off-by: Marek Vasut <[e-mail]>
Signed-off-by: David Woodhouse <[e-mail]>

drivers/mtd/nand/plat_nand.c

···
 	struct resource *res;
 	int err = 0;
 
+	if (pdata->chip.nr_chips < 1) {
+		dev_err(&pdev->dev, "invalid number of chips specified\n");
+		return -EINVAL;
+	}
+
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
 		return -ENXIO;