media: adv7842: Avoid possible out-of-bounds array accesses in adv7842_cp_log_status()

media: adv7842: Avoid possible out-of-bounds array accesses in adv7842_cp_log_status()

It's possible for cp_read() and hdmi_read() to return -EIO. Those
values are further used as indexes for accessing arrays.

Fix that by checking return values where it's needed.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: a89bcd4c6c20 ("[media] adv7842: add new video decoder driver")
Cc: stable@vger.kernel.org
Signed-off-by: Ivan Abramov <i.abramov@mt-integration.ru>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>