net: dsa: mv88e6xxx: Fix fwnode reference leaks in mv88e6xxx_port_setup_leds

net: dsa: mv88e6xxx: Fix fwnode reference leaks in mv88e6xxx_port_setup_leds

Fix multiple fwnode reference leaks:

1. The function calls fwnode_get_named_child_node() to get the "leds" node,
   but never calls fwnode_handle_put(leds) to release this reference.

2. Within the fwnode_for_each_child_node() loop, the early return
   paths that don't properly release the "led" fwnode reference.

This fix follows the same pattern as commit d029edefed39
("net dsa: qca8k: fix usages of device_get_named_child_node()")

Fixes: 94a2a84f5e9e ("net: dsa: mv88e6xxx: Support LED control")
Cc: stable@vger.kernel.org
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patch.msgid.link/20250901073224.2273103-1-linmq006@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>