drm/tegra: fb: Properly release GEM objects on failure

When fbdev initialization fails, make sure to unreference the GEM
objects properly. Note that we can't do this in the general error
unwinding path because ownership of the GEM object references is
transferred to the framebuffer upon creation.
Signed-off-by: NThierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/fb.c

@@ -227,7 +227,7 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
 	info = framebuffer_alloc(0, drm->dev);
 	if (!info) {
 		dev_err(drm->dev, "failed to allocate framebuffer info\n");
-		tegra_bo_free_object(&bo->gem);
+		drm_gem_object_unreference_unlocked(&bo->gem);
 		return -ENOMEM;
 	}
 
@@ -235,6 +235,7 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
 	if (IS_ERR(fbdev->fb)) {
 		dev_err(drm->dev, "failed to allocate DRM framebuffer\n");
 		err = PTR_ERR(fbdev->fb);
+		drm_gem_object_unreference_unlocked(&bo->gem);
 		goto release;
 	}