mtd: spi-nor: Fix spi_nor_try_unlock_all()

mtd: spi-nor: Fix spi_nor_try_unlock_all()

Commit ff67592cbdfc ("mtd: spi-nor: Introduce spi_nor_set_mtd_info()")
moved all initialization of the mtd fields at the end of spi_nor_scan().
Normally, the mtd info is only needed for the mtd ops on the device,
with one exception: spi_nor_try_unlock_all(), which will also make use
of the mtd->size parameter. With that commit, the size will always be
zero because it is not initialized. Fix that by not using the size of
the mtd_info struct, but use the size from struct spi_nor_flash_parameter.

Fixes: ff67592cbdfc ("mtd: spi-nor: Introduce spi_nor_set_mtd_info()")
Cc: stable@vger.kernel.org
Reported-by: Jean-Marc Ranger <jmranger@hotmail.com>
Closes: https://lore.kernel.org/all/DM6PR06MB561177323DC5207E34AF2A06C547A@DM6PR06MB5611.namprd06.prod.outlook.com/
Tested-by: Jean-Marc Ranger <jmranger@hotmail.com>
Signed-off-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Link: https://lore.kernel.org/r/20250701140426.2355182-1-mwalle@kernel.org