drm/i915/guc: Update CTB helpers to use CT_ERROR

drm/i915/guc: Update CTB helpers to use CT_ERROR

Update GuC CTB action helpers to benefit from new CT_ERROR macro.

Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200111231114.59208-4-michal.wajdeczko@intel.com