Staging: iio: some uninitialized variable bugs

There were some uninitialized variable warnings in iio.  Two of
these came from the recent changes to how the private data was
allocated in 83f0422dc6a16 "staging:iio:accel:sca3000: allocate
state in iio_dev and use iio_priv to access."

drivers/staging/iio/accel/sca3000_core.c: In function 'sca3000_probe':
drivers/staging/iio/accel/sca3000_core.c:1137:9: warning: 'st' may be used uninitialized in this function
drivers/staging/iio/adc/ad7291.c: In function 'ad7291_probe':
drivers/staging/iio/adc/ad7291.c:805:15: warning: 'chip' may be used uninitialized in this function
drivers/staging/iio/dac/ad5624r_spi.c: In function 'ad5624r_probe':
drivers/staging/iio/dac/ad5624r_spi.c:228:24: warning: 'st' may be used uninitialized in this function

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/accel/sca3000_core.c

@@ -1133,6 +1133,7 @@ static int __devinit sca3000_probe(struct spi_device *spi)
 		goto error_ret;
 	}
 
+	st = iio_priv(indio_dev);
 	spi_set_drvdata(spi, indio_dev);
 	st->us = spi;
 	mutex_init(&st->lock);

drivers/staging/iio/adc/ad7291.c

@@ -799,6 +799,7 @@ static int __devinit ad7291_probe(struct i2c_client *client,
 		ret = -ENOMEM;
 		goto error_ret;
 	}
+	chip = iio_priv(indio_dev);
 	/* this is only used for device removal purposes */
 	i2c_set_clientdata(client, indio_dev);
 

drivers/staging/iio/dac/ad5624r_spi.c

@@ -276,7 +276,7 @@ error_free_dev:
 	iio_free_device(indio_dev);
 error_disable_reg:
 	if (!IS_ERR(reg))
-		regulator_disable(st->reg);
+		regulator_disable(reg);
 error_put_reg:
 	if (!IS_ERR(reg))
 		regulator_put(reg);