hwmon: (ads7871) Fix ads7871_probe error paths

1. remove 'status' variable
2. remove unneeded initialization of 'err' variable
3. return missing error code if sysfs_create_group fail.
4. fix the init sequence as:
   - check hardware existence
   - kzalloc for ads7871_data
   - sysfs_create_group
   - hwmon_device_register
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NJean Delvare <khali@linux-fr.org>

drivers/hwmon/ads7871.c

@@ -160,30 +160,12 @@ static const struct attribute_group ads7871_group = {
 
 static int __devinit ads7871_probe(struct spi_device *spi)
 {
-	int status, ret, err = 0;
+	int ret, err;
 	uint8_t val;
 	struct ads7871_data *pdata;
 
 	dev_dbg(&spi->dev, "probe\n");
 
-	pdata = kzalloc(sizeof(struct ads7871_data), GFP_KERNEL);
-	if (!pdata) {
-		err = -ENOMEM;
-		goto exit;
-	}
-
-	status = sysfs_create_group(&spi->dev.kobj, &ads7871_group);
-	if (status < 0)
-		goto error_free;
-
-	pdata->hwmon_dev = hwmon_device_register(&spi->dev);
-	if (IS_ERR(pdata->hwmon_dev)) {
-		err = PTR_ERR(pdata->hwmon_dev);
-		goto error_remove;
-	}
-
-	spi_set_drvdata(spi, pdata);
-
 	/* Configure the SPI bus */
 	spi->mode = (SPI_MODE_0);
 	spi->bits_per_word = 8;
@@ -201,6 +183,24 @@ static int __devinit ads7871_probe(struct spi_device *spi)
 	we need to make sure we really have a chip*/
 	if (val != ret) {
 		err = -ENODEV;
+		goto exit;
+	}
+
+	pdata = kzalloc(sizeof(struct ads7871_data), GFP_KERNEL);
+	if (!pdata) {
+		err = -ENOMEM;
+		goto exit;
+	}
+
+	err = sysfs_create_group(&spi->dev.kobj, &ads7871_group);
+	if (err < 0)
+		goto error_free;
+
+	spi_set_drvdata(spi, pdata);
+
+	pdata->hwmon_dev = hwmon_device_register(&spi->dev);
+	if (IS_ERR(pdata->hwmon_dev)) {
+		err = PTR_ERR(pdata->hwmon_dev);
 		goto error_remove;
 	}