moxa: switch to ->[sg]et_serial()

Pointless dead assignments in moxa_set_serial_info() killed off;
they would've been a bug, if not for the fact that user-settable
flags had never been used in that driver.  Bogus from day 1,
though...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
1 file changed