Input: wacom - remove passing id for wacom_set_report

Every call of wacom_set_report was passing "id" as a separate parameter
and buffer also passed the same information. We can use first u8 of the
buffer instead of "id"

Signed-off-by: Przemo Firszt <przemo@firszt.eu>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Ping Cheng <pingc@wacom.com>
Tested-by: Przemo Firszt <przemo@firszt.eu>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>