drm/rockchip: cleanup fb when drm_gem_fb_afbc_init failed

drm/rockchip: cleanup fb when drm_gem_fb_afbc_init failed

In the function drm_gem_fb_init_with_funcs, the framebuffer (fb)
and its corresponding object ID have already been registered.

So we need to cleanup the drm framebuffer if the subsequent
execution of drm_gem_fb_afbc_init fails.

Directly call drm_framebuffer_put to ensure that all fb related
resources are cleanup.

Fixes: 7707f7227f09 ("drm/rockchip: Add support for afbc")
Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20250509031607.2542187-1-andyshrk@163.com