xfrm: remove redundant assignments

These assignments are overwritten within the same function further down

commit e8961c50ee9cc ("xfrm: Refactor migration setup
during the cloning process")
x->props.family = m->new_family;

Which actually moved it in the
commit e03c3bba351f9 ("xfrm: Fix xfrm migrate issues when address family changes")

And the initial
commit 80c9abaabf428 ("[XFRM]: Extension for dynamic update of endpoint address(es)")

added x->props.saddr = orig->props.saddr; and
memcpy(&xc->props.saddr, &m->new_saddr, sizeof(xc->props.saddr));

Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>