iio: adc: max1363: simplify with cleanup.h

Allocate the memory with scoped/cleanup.h to reduce error handling and
make the code a bit simpler.
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://patch.msgid.link/20240705-cleanup-h-iio-v1-4-77114c7e84c5@linaro.orgSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/max1363.c

@@ -13,6 +13,7 @@
   */
 
 #include <linux/interrupt.h>
+#include <linux/cleanup.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/sysfs.h>
@@ -818,7 +819,6 @@ static int max1363_read_event_config(struct iio_dev *indio_dev,
 
 static int max1363_monitor_mode_update(struct max1363_state *st, int enabled)
 {
-	u8 *tx_buf;
 	int ret, i = 3, j;
 	unsigned long numelements;
 	int len;
@@ -850,11 +850,10 @@ static int max1363_monitor_mode_update(struct max1363_state *st, int enabled)
 	}
 	numelements = bitmap_weight(modemask, MAX1363_MAX_CHANNELS);
 	len = 3 * numelements + 3;
-	tx_buf = kmalloc(len, GFP_KERNEL);
-	if (!tx_buf) {
-		ret = -ENOMEM;
-		goto error_ret;
-	}
+	u8 *tx_buf __free(kfree) = kmalloc(len, GFP_KERNEL);
+	if (!tx_buf)
+		return -ENOMEM;
+
 	tx_buf[0] = st->configbyte;
 	tx_buf[1] = st->setupbyte;
 	tx_buf[2] = (st->monitor_speed << 1);
@@ -893,11 +892,9 @@ static int max1363_monitor_mode_update(struct max1363_state *st, int enabled)
 
 	ret = st->send(st->client, tx_buf, len);
 	if (ret < 0)
-		goto error_ret;
-	if (ret != len) {
-		ret = -EIO;
-		goto error_ret;
-	}
+		return ret;
+	if (ret != len)
+		return -EIO;
 
 	/*
 	 * Now that we hopefully have sensible thresholds in place it is
@@ -910,18 +907,13 @@ static int max1363_monitor_mode_update(struct max1363_state *st, int enabled)
 	tx_buf[1] = MAX1363_MON_INT_ENABLE | (st->monitor_speed << 1) | 0xF0;
 	ret = st->send(st->client, tx_buf, 2);
 	if (ret < 0)
-		goto error_ret;
-	if (ret != 2) {
-		ret = -EIO;
-		goto error_ret;
-	}
-	ret = 0;
-	st->monitor_on = true;
-error_ret:
+		return ret;
+	if (ret != 2)
+		return -EIO;
 
-	kfree(tx_buf);
+	st->monitor_on = true;
 
-	return ret;
+	return 0;
 }
 
 /*