drm/tegra: Stop using drm_framebuffer_unregister_private

This is the deprecated function for when you embedded the framebuffer
somewhere else (which breaks refcounting). But Tegra is using
drm_framebuffer_remove and a free-standing FB, so this is redundant.

One caveat here is that the failure path in the init code still
manually cleaned up the fb. I presume that was an oversight and
changed it over to drm_framebuffer_remove too.

Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: Archit Taneja <architt@codeaurora.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1482835765-12044-5-git-send-email-daniel.vetter@ffwll.ch
Link: http://patchwork.freedesktop.org/patch/msgid/1482835765-12044-2-git-send-email-daniel.vetter@ffwll.ch

drivers/gpu/drm/tegra/fb.c

@@ -271,8 +271,7 @@ static int tegra_fbdev_probe(struct drm_fb_helper *helper,
 	return 0;
 
 destroy:
-	drm_framebuffer_unregister_private(fb);
-	tegra_fb_destroy(fb);
+	drm_framebuffer_remove(fb);
 release:
 	drm_fb_helper_release_fbi(helper);
 	return err;
@@ -342,10 +341,8 @@ static void tegra_fbdev_exit(struct tegra_fbdev *fbdev)
 	drm_fb_helper_unregister_fbi(&fbdev->base);
 	drm_fb_helper_release_fbi(&fbdev->base);
 
-	if (fbdev->fb) {
-		drm_framebuffer_unregister_private(&fbdev->fb->base);
+	if (fbdev->fb)
 		drm_framebuffer_remove(&fbdev->fb->base);
-	}
 
 	drm_fb_helper_fini(&fbdev->base);
 	tegra_fbdev_free(fbdev);