drm/gma500: Do not clear framebuffer GEM objects during cleanup

Gma500 unnecessarily clears the framebuffer's GEM-object pointer
before calling drm_framebuffer_cleanup(). Remove this code to make
gma500 consistent with the rest of the drivers.

The change is cosmetic, as drm_framebuffer_cleanup() does not
touch the object pointer on gma500.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Link: https://lore.kernel.org/r/20250904121157.395128-1-tzimmermann@suse.de

Author: tdz

drivers/gpu/drm/gma500/fbdev.c

@@ -120,7 +120,6 @@ static void psb_fbdev_fb_destroy(struct fb_info *info)
 	drm_fb_helper_fini(fb_helper);
 
 	drm_framebuffer_unregister_private(fb);
-	fb->obj[0] = NULL;
 	drm_framebuffer_cleanup(fb);
 	kfree(fb);
 
@@ -245,7 +244,6 @@ int psb_fbdev_driver_fbdev_probe(struct drm_fb_helper *fb_helper,
 
 err_drm_framebuffer_unregister_private:
 	drm_framebuffer_unregister_private(fb);
-	fb->obj[0] = NULL;
 	drm_framebuffer_cleanup(fb);
 	kfree(fb);
 err_drm_gem_object_put: