Remove paragraph which describes how we might switch our packet queueing

discipline to Random Early Detection (RED) in the future.  The same para
incorrectly spelt ``Random Early Detection'' as ``Random Early Drop''.

While I am there, nuke IF_ENQ_DROP from the list of functions.  More
work will be done on this, since some of the functions like
if_enq_drop() and if_queue_drop() were replaced with one function
called if_handoff() that does the job of enqueing the packet and
updating interface statistics as necessary.

Reviewed by:		wollman
Approved by:		des (mentor)
MFC after:		1 day

share/man/man9/ifnet.9

@@ -81,7 +81,6 @@
 .Ft "struct ifmultiaddr *"
 .Fn ifmaof_ifpforaddr "struct sockaddr *addr" "struct ifnet *ifp"
 .Ss "Output queue macros"
-.Fn IF_ENQ_DROP "struct ifqueue *ifq" "struct mbuf *m"
 .Fn IF_DEQUEUE "struct ifqueue *ifq" "struct mbuf *m"
 .\"
 .Ss "struct ifnet Member Functions"
@@ -207,18 +206,6 @@ Interfaces are also associated with an output queue, defined as a
 .Vt "struct ifqueue" ;
 this structure is used to hold packets while the interface is in the
 process of sending another.
-The current implementation implements a
-drop-tail queuing discipline, but in the future a Random Early Drop
-discipline is expected to be used.
-For this reason, kernel code
-should not depend on the internals of the queue structure; in
-particular, only the
-.Fn IF_ENQ_DROP
-and
-.Fn IF_DEQUEUE
-macros will be supported in future implementations.
-.\" The old structure will probably be retained for compatibility
-.\" under a different name.
 .Pp
 .Ss The Vt ifnet Ss structure
 The fields of