EDAC/versalnet: Fix device_node leak in mc_probe()

In the Linux kernel, the following vulnerability has been resolved: EDAC/versalnet: Fix device_node leak in mc_probe() of_parse_phandle() returns a device_node reference that must be released with of_node_put(). The original code never freed r5_core_node on any exit path, causing a memory leak. Fix this by using the automatic cleanup attribute __free(device_node) which ensures of_node_put() is called when the variable goes out of scope.