56ea4e4fa6
Not everyone has a copy class, so don't dereference it if it's not
set.
Pointed out on irc by Armada
Fixes: 65092ab1a5 ("nouveau/nvc0: add support for using common pushbuf dumper")
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30421>