UPSTREAM: ACPI: device property: Fix node lookup in acpi_graph_get_child_prop_value()

acpi_graph_get_child_prop_value() is intended to find a child node with a
certain property value pair. The check

	if (!fwnode_property_read_u32(fwnode, prop_name, &nr))
		continue;

is faulty: fwnode_property_read_u32() returns zero on success, not on
failure, leading to comparing values only if the searched property was not
found.

Moreover, the check is made against the parent device node instead of
the child one as it should be.

Fixes: 79389a83bc38 (ACPI / property: Add support for remote endpoints)
Reported-by: Hyungwoo Yang <hyungwoo.yang@intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: 4.12+ <stable@vger.kernel.org> # 4.12+
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

(cherry picked from commit b5212f57da145e53df790a7e211d94daac768bf8)
Signed-off-by: Brian J Lovin <brian.j.lovin@intel.com>

BUG=b:64133998
TEST=media device topology shows subdevs registered successfully
TEST=no camera regression

Change-Id: Ib52ce57f19672c3c15fab66b3abc94dc6d61eb6b
Reviewed-on: https://chromium-review.googlesource.com/693683
Commit-Ready: Tomasz Figa <tfiga@chromium.org>
Tested-by: Hyungwoo Yang <hyungwoo.yang@intel.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Jacob Chen <jacob2.chen@rock-chips.com>

Author: Sakari Ailus

drivers/acpi/property.c

@@ -1047,7 +1047,7 @@ static struct fwnode_handle *acpi_graph_get_child_prop_value(
 	fwnode_for_each_child_node(fwnode, child) {
 		u32 nr;
 
-		if (!fwnode_property_read_u32(fwnode, prop_name, &nr))
+		if (fwnode_property_read_u32(child, prop_name, &nr))
 			continue;
 
 		if (val == nr)