Revert "xfrm: update SA curlft.use_time"

Revert "xfrm: update SA curlft.use_time"

[ Upstream commit 717ada9f10f2de8c4f4d72ad045f3b67a7ced715 ]

This reverts commit af734a26a1a95a9fda51f2abb0c22a7efcafd5ca.

The abvoce commit is a regression according RFC 2367. A better fix would be
use x->lastused. Which will be propsed later.

according to RFC 2367 use_time == sadb_lifetime_usetime.

"sadb_lifetime_usetime
                   For CURRENT, the time, in seconds, when association
                   was first used. For HARD and SOFT, the number of
                   seconds after the first use of the association until
                   it expires."

Fixes: af734a26a1a9 ("xfrm: update SA curlft.use_time")
Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>