[PATCH 3/4] iio: magnetometer: rm3100: Use guard(mutex)() in rm3100_set_samp_freq()

[Maxwell Doose]

Replace mutex_lock() and mutex_unlock() calls in rm3100_set_samp_freq
with the more modern guard(mutex)(). This will help modernize the
driver and bring it up-to-date with modern available macros/functions.

While at it, remove unlock_return goto and use direct returns instead.

Signed-off-by: Maxwell Doose <m32285159@xxxxxxxxx>
---
 drivers/iio/magnetometer/rm3100-core.c | 25 +++++++++----------------
 1 file changed, 9 insertions(+), 16 deletions(-)

diff --git a/drivers/iio/magnetometer/rm3100-core.c b/drivers/iio/magnetometer/rm3100-core.c
index 76824dcb1b73..a2c3448e296c 100644
--- a/drivers/iio/magnetometer/rm3100-core.c
+++ b/drivers/iio/magnetometer/rm3100-core.c
@@ -334,56 +334,49 @@ static int rm3100_set_samp_freq(struct iio_dev *indio_dev, int val, int val2)
 	int ret;
 	int i;
 
-	mutex_lock(&data->lock);
+	guard(mutex)(&data->lock);
 	/* All cycle count registers use the same value. */
 	ret = regmap_read(regmap, RM3100_REG_CC_X, &cycle_count);
 	if (ret < 0)
-		goto unlock_return;
+		return ret;
 
 	for (i = 0; i < RM3100_SAMP_NUM; i++) {
 		if (val == rm3100_samp_rates[i][0] &&
 		    val2 == rm3100_samp_rates[i][1])
 			break;
 	}
-	if (i == RM3100_SAMP_NUM) {
-		ret = -EINVAL;
-		goto unlock_return;
-	}
+	if (i == RM3100_SAMP_NUM)
+		return -EINVAL;
 
 	ret = regmap_write(regmap, RM3100_REG_TMRC, i + RM3100_TMRC_OFFSET);
 	if (ret < 0)
-		goto unlock_return;
+		return ret;
 
 	/* Checking if cycle count registers need changing. */
 	if (val == 600 && cycle_count == 200) {
 		ret = rm3100_set_cycle_count(data, 100);
 		if (ret < 0)
-			goto unlock_return;
+			return ret;
 	} else if (val != 600 && cycle_count == 100) {
 		ret = rm3100_set_cycle_count(data, 200);
 		if (ret < 0)
-			goto unlock_return;
+			return ret;
 	}
 
 	if (iio_buffer_enabled(indio_dev)) {
 		/* Writing TMRC registers requires CMM reset. */
 		ret = regmap_write(regmap, RM3100_REG_CMM, 0);
 		if (ret < 0)
-			goto unlock_return;
+			return ret;
 		ret = regmap_write(data->regmap, RM3100_REG_CMM,
 			(*indio_dev->active_scan_mask & 0x7) <<
 			RM3100_CMM_AXIS_SHIFT | RM3100_CMM_START);
 		if (ret < 0)
-			goto unlock_return;
+			return ret;
 	}
-	mutex_unlock(&data->lock);
 
 	data->conversion_time = rm3100_samp_rates[i][2] * 2;
 	return 0;
-
-unlock_return:
-	mutex_unlock(&data->lock);
-	return ret;
 }
 
 static int rm3100_read_raw(struct iio_dev *indio_dev,
-- 
2.53.0