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.

Fixes: f24be42a ("cxl: Add psl9 specific code")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Acked-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220605060038.62217-1-linmq006@gmail.com