mtd: maps: Fix refcount leak in of_flash_probe_versatile
In the Linux kernel, the following vulnerability has been resolved:

mtd: maps: Fix refcount leak in of_flash_probe_versatile

of_find_matching_node_and_match() 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.