i2c: core: decrease reference count of device node in i2c_unregister_device

Reference count of device node was increased in of_i2c_register_device,
but without decreasing it in i2c_unregister_device. Then the added
device node will never be released. Fix this by adding the of_node_put.
Signed-off-by: NLixin Wang <alan.1.wang@nokia-sbell.com>
Tested-by: NWolfram Sang <wsa@the-dreams.de>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>
Cc: stable@kernel.org

drivers/i2c/i2c-core-base.c

@@ -821,8 +821,12 @@ void i2c_unregister_device(struct i2c_client *client)
 {
 	if (!client)
 		return;
-	if (client->dev.of_node)
+
+	if (client->dev.of_node) {
 		of_node_clear_flag(client->dev.of_node, OF_POPULATED);
+		of_node_put(client->dev.of_node);
+	}
+
 	if (ACPI_COMPANION(&client->dev))
 		acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
 	device_unregister(&client->dev);