drm/i915/uc: Skip reset preparation if GuC is already dead

We may skip reset preparation steps if GuC is already sanitized.

v2: replace USES_GUC with guc_is_loaded
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: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190522193203.23932-10-michal.wajdeczko@intel.com

drivers/gpu/drm/i915/intel_uc.c

@@ -493,7 +493,7 @@ void intel_uc_reset_prepare(struct drm_i915_private *i915)
 {
 	struct intel_guc *guc = &i915->guc;
 
-	if (!USES_GUC(i915))
+	if (!intel_guc_is_loaded(guc))
 		return;
 
 	guc_stop_communication(guc);