staging: mt29f_spinand: remove useless mtd->priv = chip assignment

mtd_to_nand() now uses the container_of() approach to transform an
mtd_info pointer into a nand_chip one. Drop useless mtd->priv
assignments from NAND controller drivers.
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/staging/mt29f_spinand/mt29f_spinand.c

@@ -907,7 +907,6 @@ static int spinand_probe(struct spi_device *spi_nand)
 
 	dev_set_drvdata(&spi_nand->dev, mtd);
 
-	mtd->priv = chip;
 	mtd->dev.parent = &spi_nand->dev;
 	mtd->oobsize = 64;