tcp: update the outdated ref draft-ietf-tcpm-rack

As RACK-TLP was published as a standards-track RFC8985,
so the outdated ref draft-ietf-tcpm-rack need to be updated.

Signed-off-by: Xin Guo <[e-mail]>
Reviewed-by: Neal Cardwell <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

Documentation/networking/ip-sysctl.rst

···
 
 tcp_early_retrans - INTEGER
 	Tail loss probe (TLP) converts RTOs occurring due to tail
-	losses into fast recovery (draft-ietf-tcpm-rack). Note that
+	losses into fast recovery (RFC8985). Note that
 	TLP requires RACK to function properly (see tcp_recovery below)
 
 	Possible values:

net/ipv4/tcp_input.c

···
 }
 
 /* This routine deals with acks during a TLP episode and ends an episode by
- * resetting tlp_high_seq. Ref: TLP algorithm in draft-ietf-tcpm-rack
+ * resetting tlp_high_seq. Ref: TLP algorithm in RFC8985
  */
 static void tcp_process_tlp_ack(struct sock *sk, u32 ack, int flag)
 {

net/ipv4/tcp_recovery.c

···
 	       tcp_stamp_us_delta(tp->tcp_mstamp, tcp_skb_timestamp_us(skb));
 }
 
-/* RACK loss detection (IETF draft draft-ietf-tcpm-rack-01):
+/* RACK loss detection (IETF RFC8985):
  *
  * Marks a packet lost, if some packet sent later has been (s)acked.
  * The underlying idea is similar to the traditional dupthresh and FACK