hwmon: (ad7314) Adds missing spi_dev initialization

This driver was recently moved from IIO (where it worked) to hwmon (where
it doesn't.) This breakage occured because the hwmon version neglected to
correctly initialize a reference to spi_dev in its drvdata. The result is a
segfault every time the temperature is queried.
Signed-off-by: Graeme Smecher <gsmecher@threespeedlogic.com>
Cc: stable@vger.kernel.org # 3.2+
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

drivers/hwmon/ad7314.c

@@ -128,6 +128,7 @@ static int __devinit ad7314_probe(struct spi_device *spi_dev)
 		ret = PTR_ERR(chip->hwmon_dev);
 		goto error_remove_group;
 	}
+	chip->spi_dev = spi_dev;
 
 	return 0;
 error_remove_group: