[PATCH v2] of: property: decrement node refcount in of_fwnode_get_reference_args()

[Yang Yingliang <yangyingliang@huawei.com>]

I got the the following report:

  OF: ERROR: memory leak, expected refcount 1 instead of 4,
  of_node_get()/of_node_put() unbalanced - destroy cset entry:
  attach overlay node /i2c/pmic@34/adc

In of_fwnode_get_reference_args(), the refcount of of_args.np has
been incremented in the case of successful return from
of_parse_phandle_with_args() or of_parse_phandle_with_fixed_args().

Decrement the refcount if of_args is not returned to the caller of
of_fwnode_get_reference_args().

Fixes: 3e3119d3088f ("device property: Introduce fwnode_property_get_reference_args")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
---
v1 -> v2:
  Update title and commit message that suggested by Frank.
---
 drivers/of/property.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/of/property.c b/drivers/of/property.c
index 967f79b59016..134cfc980b70 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -993,8 +993,10 @@ of_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
 						       nargs, index, &of_args);
 	if (ret < 0)
 		return ret;
-	if (!args)
+	if (!args) {
+		of_node_put(of_args.np);
 		return 0;
+	}
 
 	args->nargs = of_args.args_count;
 	args->fwnode = of_fwnode_handle(of_args.np);
-- 
2.25.1