[PATCH v3 02/13] iio: adc: at91-sama5d2_adc: use cleanup.h for NVMEM buffer

[Varshini Rajendran <varshini.rajendran@microchip.com>]

Use __free(kfree) cleanup helper for the NVMEM data buffer in
at91_adc_temp_sensor_init() to simplify error handling paths.

Since __free(kfree) requires a valid kfree-able pointer (not an
ERR_PTR), store nvmem_cell_read() result in a temporary void pointer
first, check for errors, then assign to the managed buffer.

Signed-off-by: Varshini Rajendran <varshini.rajendran@microchip.com>
---
 drivers/iio/adc/at91-sama5d2_adc.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/adc/at91-sama5d2_adc.c b/drivers/iio/adc/at91-sama5d2_adc.c
index 255970b2e747..5015c234289e 100644
--- a/drivers/iio/adc/at91-sama5d2_adc.c
+++ b/drivers/iio/adc/at91-sama5d2_adc.c
@@ -2251,9 +2251,10 @@ static int at91_adc_temp_sensor_init(struct at91_adc_state *st,
 {
 	struct at91_adc_temp_sensor_clb *clb = &st->soc_info.temp_sensor_clb;
 	struct nvmem_cell *temp_calib;
-	u32 *buf;
+	u32 *buf __free(kfree) = NULL;
+	void *cell_data;
 	size_t len;
-	int ret = 0;
+	int ret;
 
 	if (!st->soc_info.platform->temp_sensor)
 		return 0;
@@ -2267,16 +2268,18 @@ static int at91_adc_temp_sensor_init(struct at91_adc_state *st,
 		return ret;
 	}
 
-	buf = nvmem_cell_read(temp_calib, &len);
+	cell_data = nvmem_cell_read(temp_calib, &len);
 	nvmem_cell_put(temp_calib);
-	if (IS_ERR(buf)) {
+	if (IS_ERR(cell_data)) {
 		dev_err(dev, "Failed to read calibration data!\n");
-		return PTR_ERR(buf);
+		return PTR_ERR(cell_data);
 	}
+
+	buf = cell_data;
+
 	if (len < AT91_ADC_TS_CLB_IDX_MAX * 4) {
 		dev_err(dev, "Invalid calibration data!\n");
-		ret = -EINVAL;
-		goto free_buf;
+		return -EINVAL;
 	}
 
 	/* Store calibration data for later use. */
@@ -2289,9 +2292,7 @@ static int at91_adc_temp_sensor_init(struct at91_adc_state *st,
 	 */
 	clb->p1 = clb->p1 * 1000;
 
-free_buf:
-	kfree(buf);
-	return ret;
+	return 0;
 }
 
 static int at91_adc_probe(struct platform_device *pdev)
-- 
2.34.1