staging: iio: ak8975: Remove i2c client data corruption

i2c client data set is of type struct indio_dev pointer and hence the
pointer returned from i2c_get_clientdata() should be assigned to
an object of type struct indio_dev and not to an object of type
struct ak8975_data.

Also in ak8975_probe() client data should be set first
before calling ak8975_setup() as it references the client data.

Signed-off-by: Preetham Chandru R <pchandru@nvidia.com>
CC: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/magnetometer/ak8975.c

@@ -108,7 +108,8 @@ static const int ak8975_index_to_reg[] = {
 static int ak8975_write_data(struct i2c_client *client,
 			     u8 reg, u8 val, u8 mask, u8 shift)
 {
-	struct ak8975_data *data = i2c_get_clientdata(client);
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct ak8975_data *data = iio_priv(indio_dev);
 	u8 regval;
 	int ret;
 
@@ -159,7 +160,8 @@ static int ak8975_read_data(struct i2c_client *client,
  */
 static int ak8975_setup(struct i2c_client *client)
 {
-	struct ak8975_data *data = i2c_get_clientdata(client);
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct ak8975_data *data = iio_priv(indio_dev);
 	u8 device_id;
 	int ret;
 
@@ -509,6 +511,7 @@ static int ak8975_probe(struct i2c_client *client,
 		goto exit_gpio;
 	}
 	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
 	/* Perform some basic start-of-day setup of the device. */
 	err = ak8975_setup(client);
 	if (err < 0) {
@@ -516,7 +519,6 @@ static int ak8975_probe(struct i2c_client *client,
 		goto exit_free_iio;
 	}
 
-	i2c_set_clientdata(client, indio_dev);
 	data->client = client;
 	mutex_init(&data->lock);
 	data->eoc_irq = client->irq;