net: ping6: support packet timestamping

Nothing prevents the user from requesting timestamping
on ping6 sockets, yet timestamps are not going to be reported.
Plumb the flags through.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ping.c

@@ -113,6 +113,7 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
 	ipcm6_init_sk(&ipc6, np);
 	ipc6.sockc.mark = sk->sk_mark;
+	ipc6.sockc.tsflags = sk->sk_tsflags;
 	fl6.flowlabel = ip6_make_flowinfo(ipc6.tclass, fl6.flowlabel);
 
 	dst = ip6_sk_dst_lookup_flow(sk, &fl6, daddr, false);