iio: Fix fwnode_handle in __fwnode_iio_channel_get_by_name()

iio: Fix fwnode_handle in __fwnode_iio_channel_get_by_name()

In the fwnode_iio_channel_get_by_name(), iterating over parent nodes to
acquire IIO channels via fwnode_for_each_parent_node(). The variable
chan was mistakenly attempted on the original node instead of the
current parent node. This patch corrects the logic to ensure that
__fwnode_iio_channel_get_by_name() is called with the correct parent
node.

Cc: stable@vger.kernel.org # v6.6+
Fixes: 1e64b9c5f9a0 ("iio: inkern: move to fwnode properties")
Signed-off-by: Zicheng Qu <quzicheng@huawei.com>
Link: https://patch.msgid.link/20241102092525.2389952-1-quzicheng@huawei.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>