l2tp: adjust comments about L2TPv3 offsets

The "offset" option has been removed by
commit 900631ee6a26 ("l2tp: remove configurable payload offset").

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Acked-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/l2tp.h

@@ -65,7 +65,7 @@ struct sockaddr_l2tpip6 {
  * TUNNEL_MODIFY	- CONN_ID, udpcsum
  * TUNNEL_GETSTATS	- CONN_ID, (stats)
  * TUNNEL_GET		- CONN_ID, (...)
- * SESSION_CREATE	- SESSION_ID, PW_TYPE, offset, data_seq, cookie, peer_cookie, offset, l2spec
+ * SESSION_CREATE	- SESSION_ID, PW_TYPE, data_seq, cookie, peer_cookie, l2spec
  * SESSION_DELETE	- SESSION_ID
  * SESSION_MODIFY	- SESSION_ID, data_seq
  * SESSION_GET		- SESSION_ID, (...)

net/l2tp/l2tp_core.c

@@ -662,10 +662,9 @@ discard:
  * |x|S|x|x|x|x|x|x|              Sequence Number                  |
  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
  *
- * Cookie value, sublayer format and offset (pad) are negotiated with
- * the peer when the session is set up. Unlike L2TPv2, we do not need
- * to parse the packet header to determine if optional fields are
- * present.
+ * Cookie value and sublayer format are negotiated with the peer when
+ * the session is set up. Unlike L2TPv2, we do not need to parse the
+ * packet header to determine if optional fields are present.
  *
  * Caller must already have parsed the frame and determined that it is
  * a data (not control) frame before coming here. Fields up to the