HID: logitech: Use HIDPP_RECEIVER_INDEX instead of 0xff

Some parts of hid-logitech-dj explicitly referred to 0xff for the
receiver index. This patch changes those references to the
HIDPP_RECEIVER_INDEX definition.

Signed-off-by: Mazin Rezk <mnrzk@protonmail.com>
Reviewed-by: Filipe Laíns <lains@archlinux.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>