HID: i2c-hid: fix GET/SET_REPORT for unnumbered reports

[ Upstream commit a5e5e03e94764148a01757b2fa4737d3445c13a6 ]

Internally kernel prepends all report buffers, for both numbered and
unnumbered reports, with report ID, therefore to properly handle unnumbered
reports we should prepend it ourselves.

For the same reason we should skip the first byte of the buffer when
calling i2c_hid_set_or_send_report() which then will take care of properly
formatting the transfer buffer based on its separate report ID argument
along with report payload.

[jkosina@suse.cz: finalize trimmed sentence in changelog as spotted by Benjamin]
Fixes: 9b5a9ae8 ("HID: i2c-hid: implement ll_driver transport-layer callbacks")
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Tested-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>