drm/i915/guc: suppress GuC-related message on non-GuC platforms

If the user doesn't override the default values of the GuC-related
kernel parameters, then on a non-GuC-based platform we shouldn't
mention that we haven't loaded the GuC firmware.

The various messages have been reordered into a least->most severe
cascade (none/INFO/INFO/ERROR) for ease of comprehension.

Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1465575685-34169-1-git-send-email-david.s.gordon@intel.com

drivers/gpu/drm/i915/intel_guc_loader.c

@@ -525,12 +525,14 @@ fail:
 		ret = 0;
 	}
 
-	if (err == 0)
+	if (err == 0 && !HAS_GUC_UCODE(dev))
+		;	/* Don't mention the GuC! */
+	else if (err == 0)
 		DRM_INFO("GuC firmware load skipped\n");
-	else if (ret == -EIO)
-		DRM_ERROR("GuC firmware load failed: %d\n", err);
-	else
+	else if (ret != -EIO)
 		DRM_INFO("GuC firmware load failed: %d\n", err);
+	else
+		DRM_ERROR("GuC firmware load failed: %d\n", err);
 
 	if (i915.enable_guc_submission) {
 		if (fw_path == NULL)