mtd: nand: fix error handling in nand_prog_page_op() #1

On success chip->legacy.waitfunc() returns the NAND status byte, but on
failure it returns a negative error code. This was never tested for and
instead the return value was interpreted as NAND status without error
checking. Add the missing error check.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20210205142725.13225-1-s.hauer@pengutronix.de

drivers/mtd/nand/raw/nand_base.c

@@ -1466,6 +1466,8 @@ int nand_prog_page_op(struct nand_chip *chip, unsigned int page,
 		chip->legacy.write_buf(chip, buf, len);
 		chip->legacy.cmdfunc(chip, NAND_CMD_PAGEPROG, -1, -1);
 		status = chip->legacy.waitfunc(chip);
+		if (status < 0)
+			return status;
 	}
 
 	if (status & NAND_STATUS_FAIL)