[XFRM] IPV6: Fix outbound RO transformation which is broken by IPsec tunnel patch.

It seems to miss RO mode path by IPv6 over IPv4 IPsec tunnel patch
when it changed semantics to check the mode from
"xfrm[i]->props.mode != XFRM_MODE_TRANSPORT" to
"xfrm[i]->props.mode == XFRM_MODE_TUNNEL" before changing address.
It also makes two incline functions __xfrm6_bundle_addr_{remote,local}
are used by nobody.

This patch fixes it.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>