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.