drm: Propagate error from drm_fb_helper_init().

The previous commit fixes the problem, these commits make sure we actually
fail properly if it happens again.

I've squashed the commits from Chris since they are all fixing one issue.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/i915/intel_fb.c

@@ -245,6 +245,7 @@ int intel_fbdev_init(struct drm_device *dev)
 {
 	struct intel_fbdev *ifbdev;
 	drm_i915_private_t *dev_priv = dev->dev_private;
+	int ret;
 
 	ifbdev = kzalloc(sizeof(struct intel_fbdev), GFP_KERNEL);
 	if (!ifbdev)
@@ -253,8 +254,13 @@ int intel_fbdev_init(struct drm_device *dev)
 	dev_priv->fbdev = ifbdev;
 	ifbdev->helper.funcs = &intel_fb_helper_funcs;
 
-	drm_fb_helper_init(dev, &ifbdev->helper, dev_priv->num_pipe,
-			   INTELFB_CONN_LIMIT);
+	ret = drm_fb_helper_init(dev, &ifbdev->helper,
+				 dev_priv->num_pipe,
+				 INTELFB_CONN_LIMIT);
+	if (ret) {
+		kfree(ifbdev);
+		return ret;
+	}
 
 	drm_fb_helper_single_add_all_connectors(&ifbdev->helper);
 	drm_fb_helper_initial_config(&ifbdev->helper, 32);