net: phy: leds: fix memory leak

In the Linux kernel, the following vulnerability has been resolved:

net: phy: leds: fix memory leak

A network restart test on a router led to an out-of-memory condition,

which was traced to a memory leak in the PHY LED trigger code.

The root cause is misuse of the devm API. The registration function

(phy_led_triggers_register) is called from phy_attach_direct, not

phy_probe, and the unregister function (phy_led_triggers_unregister)

is called from phy_detach, not phy_remove. This means the register and

unregister functions can be called multiple times for the same PHY

device, but devm-allocated memory is not freed until the driver is

unbound.

This also prevents kmemleak from detecting the leak, as the devm API

internally stores the allocated pointer.

Fix this by replacing devm_kzalloc/devm_kcalloc with standard

kzalloc/kcalloc, and add the corresponding kfree calls in the unregister

path.