In moxa specific ASPP_OQUEUE ioctl command, they apparently want
only know whether there is space in transmitter hold register.

So switch UART_LSR_TEMT to UART_LSR_THRE in that specific case
according to the change in 1.14 moxa drivers.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>