Bluetooth: rfcomm: remove casts from tty->driver_data

Bluetooth: rfcomm: remove casts from tty->driver_data

tty->driver_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: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Cc: linux-bluetooth@vger.kernel.org
Link: https://lore.kernel.org/r/20230731080244.2698-3-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>