setup: fix calling clone hook with weird params

setup: fix calling clone hook with weird params

$clone has no use and what the interface constraints on $conf vs.
$self->{conf} really are is nowhere documented, so just use $conf for
now, to at least use only one thing (and avoid the highly confusing
case where the signature suggests that $conf is used, so when one
would pass a to $self->{conf} unrelated $conf it would not work)

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>