iio: Use strict_strtouint instead of kstrtoul

strict_strto* has been deprecated in favor of kstrto*. Use strict_strtouint
respective strict_strtoint, since that is what the functions we pass the
converted values to expect.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c
index d4ad374..722a83f 100644
--- a/drivers/iio/industrialio-buffer.c
+++ b/drivers/iio/industrialio-buffer.c
@@ -371,12 +371,12 @@
 				const char *buf,
 				size_t len)
 {
-	int ret;
-	ulong val;
 	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
 	struct iio_buffer *buffer = indio_dev->buffer;
+	unsigned int val;
+	int ret;
 
-	ret = strict_strtoul(buf, 10, &val);
+	ret = kstrtouint(buf, 10, &val);
 	if (ret)
 		return ret;