input: serport: remove casts from tty->disc_data

tty->disc_data is 'void *', so there is no need to cast from that.
Therefore remove the casts and assign the pointer directly.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: linux-input@vger.kernel.org
Link: https://lore.kernel.org/r/20230731080244.2698-5-jirislaby@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>