iproute2: Remove "monitor" from "ip route help" output

$ ip route help 2>&1 | grep monitor
ip route { add | del | change | append | replace | monitor } ROUTE
$ ip route monitor
Command "monitor" is unknown, try "ip route help".

(I guess what was really intended is "ip monitor route", so just remove
the argument from the help output.)

Originally reported by martin f krafft at http://bugs.debian.org/537681

While at it, also drop all non-existant (route,link,netns) monitor
arguments from the ip(8) man page.

Signed-off-by: Andreas Henriksson <andreas@fatal.se>
diff --git a/ip/iproute.c b/ip/iproute.c
index ca09029..21e1a4b 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -63,7 +63,7 @@
 	fprintf(stderr, "       ip route get ADDRESS [ from ADDRESS iif STRING ]\n");
 	fprintf(stderr, "                            [ oif STRING ]  [ tos TOS ]\n");
 	fprintf(stderr, "                            [ mark NUMBER ]\n");
-	fprintf(stderr, "       ip route { add | del | change | append | replace | monitor } ROUTE\n");
+	fprintf(stderr, "       ip route { add | del | change | append | replace } ROUTE\n");
 	fprintf(stderr, "SELECTOR := [ root PREFIX ] [ match PREFIX ] [ exact PREFIX ]\n");
 	fprintf(stderr, "            [ table TABLE_ID ] [ proto RTPROTO ]\n");
 	fprintf(stderr, "            [ type TYPE ] [ scope SCOPE ]\n");