mtd: rawnand: Add a check in of_get_nand_secure_regions()

Check for whether of_property_count_elems_of_size() returns a negative
error code.

Fixes: 13b89768 ("mtd: rawnand: Add support for secure regions in NAND memory")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/YMtQFXE0F1w7mUh+@mwanda

drivers/mtd/nand/raw/nand_base.c

@@ -5231,8 +5231,8 @@ static int of_get_nand_secure_regions(struct nand_chip *chip)
 	int nr_elem, i, j;
 
 	nr_elem = of_property_count_elems_of_size(dn, "secure-regions", sizeof(u64));
-	if (!nr_elem)
-		return 0;
+	if (nr_elem <= 0)
+		return nr_elem;
 
 	chip->nr_secure_regions = nr_elem / 2;
 	chip->secure_regions = kcalloc(chip->nr_secure_regions, sizeof(*chip->secure_regions),