net: altera: Fix refcount leak in altera_tse_mdio_create

net: altera: Fix refcount leak in altera_tse_mdio_create

Every iteration of for_each_child_of_node() decrements
the reference count of the previous node.
When break from a for_each_child_of_node() loop,
we need to explicitly call of_node_put() on the child node when
not need anymore.
Add missing of_node_put() to avoid refcount leak.

Fixes: eaccad8b1d32 ("Altera TSE: Add main and header file for Altera Ethernet Driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220607041144.7553-1-linmq006@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>