[PATCH v2] staging: iio: frequency: ad9832: use devm_mutex_init()

[Nithishvelan M <mnithishvelan@gmail.com>]

Replace mutex_init() with devm_mutex_init() in ad9832_probe() and
check its return value. The driver already uses devm_* helpers for
its other resources and has no remove() callback, so this ensures
the mutex is destroyed automatically on teardown when mutex
debugging is enabled.

No functional change intended. Compile-tested only.

Signed-off-by: Nithishvelan M <mnithishvelan@gmail.com>
---
Changes in v2:
- Add blank line after "st->spi = spi;" (Andy)

 drivers/staging/iio/frequency/ad9832.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/iio/frequency/ad9832.c b/drivers/staging/iio/frequency/ad9832.c
index 35f823f24f..e3b4e19a8d 100644
--- a/drivers/staging/iio/frequency/ad9832.c
+++ b/drivers/staging/iio/frequency/ad9832.c
@@ -325,7 +325,10 @@ static int ad9832_probe(struct spi_device *spi)
 		return PTR_ERR(st->mclk);
 
 	st->spi = spi;
-	mutex_init(&st->lock);
+
+	ret = devm_mutex_init(&spi->dev, &st->lock);
+	if (ret)
+		return ret;
 
 	indio_dev->name = spi_get_device_id(spi)->name;
 	indio_dev->info = &ad9832_info;
-- 
2.56.0