Reading ECC status is failing.

w25n02kv_ecc_get_status() is using on-stack buffer for
SPINAND_GET_FEATURE_OP() output. It is not suitable for
DMA needs of spi-mem.

Fix this by using the spi-mem operations dedicated buffer
spinand->scratchbuf.

See
spinand->scratchbuf:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/linux/mtd/spinand.h?h=v6.3#n418
spi_mem_check_op():
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/spi/spi-mem.c?h=v6.3#n199

Fixes: 6154c7a5 ("mtd: spinand: winbond: add Winbond W25N02KV flash support")
Cc: stable@vger.kernel.org
Signed-off-by: Olivier Maignial <olivier.maignial@hotmail.fr>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/DB4P250MB1032EDB9E36B764A33769039FE23A@DB4P250MB1032.EURP250.PROD.OUTLOOK.COM