net: hso: drop unused function argument

_hso_serial_set_termios() doesn't use it's second argument, so it can be
dropped.

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/20210811171321.18317-1-paskripkin@gmail.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>