mtd: spi-nor: assign mtd->priv in spi_nor_scan()

Layering suggests that the SPI NOR layer (not the hardware driver)
should be initializing the MTD layer.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Tested-by: Joachim Eastwood <manabian@gmail.com>

drivers/mtd/devices/m25p80.c

@@ -205,7 +205,6 @@ static int m25p_probe(struct spi_device *spi)
 	nor->priv = flash;
 
 	spi_set_drvdata(spi, flash);
-	flash->mtd.priv = nor;
 	flash->spi = spi;
 
 	if (spi->mode & SPI_RX_QUAD)