This goes back to
commit 362b8af7ad
Author: Ben Widawsky <benjamin.widawsky@intel.com>
Date: Thu Jan 30 00:19:38 2014 -0800
drm/i915: Move per ring error state to ring_error
Spotted while reading error states.
Cc: Ben Widawsky <benjamin.widawsky@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>