CVE-2022-49668

In the Linux kernel, the following vulnerability has been resolved:

PM / devfreq: exynos-ppmu: Fix refcount leak in of_get_devfreq_events

of_get_child_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.
This function only calls of_node_put() in normal path,
missing it in error paths.
Add missing of_node_put() to avoid refcount leak.