xfrm: Clone states properly on migration

We loose a lot of information of the original state if we
clone it with xfrm_state_clone(). In particular, there is
no crypto algorithm attached if the original state uses
an aead algorithm. This patch add the missing information
to the clone state.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

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

diff --cc net/xfrm/xfrm_state.c
Simple merge

diff --cc net/xfrm/xfrm_user.c
Simple merge