irqchip/gic-v3: Fix error handling in gic_populate_ppi_partitions

of_get_child_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when not need anymore.
When kcalloc fails, it missing of_node_put() and results in refcount
leak. Fix this by goto out_put_node label.

Fixes: 52085d3f ("irqchip/gic-v3: Dynamically allocate PPI partition descriptors")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220601080930.31005-5-linmq006@gmail.com