CVE-2022-49680

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

ARM: exynos: Fix refcount leak in exynos_map_pmu

of_find_matching_node() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
Add missing of_node_put() to avoid refcount leak.
of_node_put() checks null pointer.