of: unittest: fix memory leak in unittest_data_add

BugLink: https://bugs.launchpad.net/bugs/1852110

[ Upstream commit e13de8fe ]

In unittest_data_add, a copy buffer is created via kmemdup. This buffer
is leaked if of_fdt_unflatten_tree fails. The release for the
unittest_data buffer is added.

Fixes: b951f9dc ("Enabling OF selftest to run without machine's devicetree")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/of/unittest.c

@@ -924,6 +924,7 @@ static int __init unittest_data_add(void)
 	of_fdt_unflatten_tree(unittest_data, &unittest_data_node);
 	if (!unittest_data_node) {
 		pr_warn("%s: No tree to attach; not running tests\n", __func__);
+		kfree(unittest_data);
 		return -ENODATA;
 	}
 	of_node_set_flag(unittest_data_node, OF_DETACHED);