drm: Warn when freeing a framebuffer that's still on a list

Sprinkle some extra WARNs around so that we might catch
premature framebuffer destruction more readily.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231211081625.25704-2-ville.syrjala@linux.intel.com


Acked-by: Javier Martinez Canillas <javierm@redhat.com>