ipv6: xfrm: use 64-bit timestamps

get_seconds() is deprecated because it can overflow on 32-bit
architectures.  For the xfrm_state->lastused member, we treat the data
as a 64-bit number already, so we just need to use the right accessor
that works on both 32-bit and 64-bit machines.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

include/net/xfrm.h

@@ -227,7 +227,7 @@ struct xfrm_state {
 	long		saved_tmo;
 
 	/* Last used time */
-	unsigned long		lastused;
+	time64_t		lastused;
 
 	struct page_frag xfrag;
 

net/ipv6/xfrm6_mode_ro.c

@@ -55,7 +55,7 @@ static int xfrm6_ro_output(struct xfrm_state *x, struct sk_buff *skb)
 	__skb_pull(skb, hdr_len);
 	memmove(ipv6_hdr(skb), iph, hdr_len);
 
-	x->lastused = get_seconds();
+	x->lastused = ktime_get_real_seconds();
 
 	return 0;
 }