I forgot the 4in6/6in4 cases in my previous patch. Let's fix them.

Fixes: 95224166 ("vti[6]: fix packet tx through bpf_redirect()")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>