mtd: use the NAND_STATUS_FAIL to replace the hardcode

Use the NAND_STATUS_FAIL to replace the hardcode "0x01",
which make the code more readable.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>