sys/linux: id field fix in v4l2_event_subscription

The id field in the v4l2_event_subscription structure
currently described as: id len[type, int32].

But all the documentation states is:
"id - ID of the event source. If there is no ID associated
with the event source, then set this to 0. Whether or not
an event needs an ID depends on the event type."

So, the documentation clearly states that:
1. id - is the source of an event
2. type - is the type of an event
3. for some types of events there is no source and id can be 0

According to this 'id int32' is more accurate description of
the field.

0 files changed, 0 insertions, 0 deletions