pmdomain: mediatek: fix use-after-free in scpsys_get_bus_protection_legacy()

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

pmdomain: mediatek: fix use-after-free in scpsys_get_bus_protection_legacy()

In scpsys_get_bus_protection_legacy(), of_find_node_with_property()

returns a device node with its reference count incremented. The function

then calls of_node_put(node) before checking whether

syscon_regmap_lookup_by_phandle() returns an error. If an error occurs,

dev_err_probe() dereferences the node pointer to print diagnostic

information, but the node memory may have already been freed due to the

earlier of_node_put(), leading to a use-after-free vulnerability.

Fix this by moving the of_node_put() call after the error check, ensuring

the node is still valid when accessed in the error path.