aa8b4d7fac
The grub_net_network_level_interface_unregister(), previously implemented in a header, did not remove the variables hooks that were registered in grub_net_network_level_interface_register(). Fix this by implementing the same logic used to register the variables and move the function into the grub-core/net/net.c. Signed-off-by: B Horn <b@horn.uk> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>