mtd: nand: remove hard-coded NAND ids length

This commit removes hard-coded '8' used for looping into
struct nand_chip.id.data array.

NAND_MAX_ID_LEN has been introduced by Artem Bityutskiy in
53552d22bfe1f for defining ids length in nand_flash_ids[] list.

This commit unifies ids length in nand base driver.

Signed-off-by: Jean-Louis Thekekara <jeanlouis.thekekara@parrot.com>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
diff --git a/drivers/mtd/nand/nand_base.c b/drivers/mtd/nand/nand_base.c
index abcb15f..ab28043 100644
--- a/drivers/mtd/nand/nand_base.c
+++ b/drivers/mtd/nand/nand_base.c
@@ -3886,7 +3886,7 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type)
 	chip->cmdfunc(mtd, NAND_CMD_READID, 0x00, -1);
 
 	/* Read entire ID string */
-	for (i = 0; i < 8; i++)
+	for (i = 0; i < ARRAY_SIZE(chip->id.data); i++)
 		id_data[i] = chip->read_byte(mtd);
 
 	if (id_data[0] != maf_id || id_data[1] != dev_id) {
@@ -3895,7 +3895,7 @@ static int nand_detect(struct nand_chip *chip, struct nand_flash_dev *type)
 		return -ENODEV;
 	}
 
-	chip->id.len = nand_id_len(id_data, 8);
+	chip->id.len = nand_id_len(id_data, ARRAY_SIZE(chip->id.data));
 
 	/* Try to identify manufacturer */
 	manufacturer = nand_get_manufacturer(maf_id);