sched, bpf: let stack handle !IFF_UP devs on bpf_clone_redirect

Similarly as already the case in bpf_redirect()/skb_do_redirect()
pair, let the stack deal with devs that are !IFF_UP.

dev_forward_skb() as well as dev_queue_xmit() will free the skb
and increment drop counter internally in such cases, so we can
spare the condition in bpf_clone_redirect().

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>