cxl: Fix refcount leak in cxl_calc_capp_routing

In the Linux kernel, the following vulnerability has been resolved: cxl: Fix refcount leak in cxl_calc_capp_routing of_get_next_parent() returns a node pointer with refcount incremented, we should use of_node_put() on it when not need anymore. This function only calls of_node_put() in normal path, missing it in the error path. Add missing of_node_put() to avoid refcount leak.