In other functions of the driver, variables of type "struct hso_serial"
are denoted by "serial" and variables of type "struct hso_device" are
denoted by "hso_dev". This patch makes the hso_free_interface()
consistent with these notations.
Signed-off-by: NOlivier Sobrie <olivier@sobrie.be>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>