drm/i915/guc: Remove stale comment for q_fail

This member was dropped long time ago.

Fixes: 774439e1 ("drm/i915/guc: re-optimise i915_guc_client layout")
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170518113104.54400-1-michal.wajdeczko@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 4afc67be)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>