inetpeer: update inetpeer timestamp in inet_getpeer()

inet_putpeer() will be removed in the following patch,
because we will no longer use refcounts.

Update inetpeer timestamp (p->dtime) at lookup time.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241215175629.1248773-4-edumazet@google.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>