ipv6: Remove external dependency on rt6i_dst and rt6i_src

This patch removes the assumptions that the returned rt is always
a RTF_CACHE entry with the rt6i_dst and rt6i_src containing the
destination and source address.  The dst and src can be recovered from
the calling site.

We may consider to rename (rt6i_dst, rt6i_src) to
(rt6i_key_dst, rt6i_key_src) later.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --cc drivers/scsi/cxgbi/libcxgbi.c
Simple merge

diff --cc include/net/ipv6.h
Simple merge

diff --cc net/ipv6/icmp.c
Simple merge

diff --cc net/ipv6/ip6_output.c
Simple merge

diff --cc net/ipv6/ndisc.c
Simple merge

diff --cc net/ipv6/output_core.c
Simple merge

diff --cc net/ipv6/tcp_ipv6.c
Simple merge

diff --cc net/netfilter/ipvs/ip_vs_xmit.c
Simple merge

diff --cc net/sctp/ipv6.c
Simple merge