drm/i915: Reattach comment, complete type specification

In the recent patch
bc3d674 drm/i915: Allow userspace to request no-error-capture upon ...
the final version moved the flags and the associated #defines around
so they were adjacent; unfortunately, they ended up between a comment
and the thing (hw_id) to which the comment applies :(

So this patch reshuffles the comment and subject back together.

Also, as we're touching 'hw_id', let's change it from just 'unsigned'
to a fully-specified 'unsigned int', because some code checking tools
(including checkpatch) object to plain 'unsigned'.

Fixes: bc3d674462e5 ("drm/i915: Allow userspace to request no-error-capture...")
Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1471616622-6919-1-git-send-email-david.s.gordon@intel.com
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit 0be81156b3fb4d4e8e2c94177e5222dc21c3ff10)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>