tc: pedit: document branch control in help output

This seems to have been a hidden feature, though it's very useful and
necessary at least when combining multiple pedit actions.
Signed-off-by: Phil Sutter <phil@nwl.cc>

tc/m_pedit.c

@@ -35,7 +35,7 @@ static int pedit_debug;
 static void
 explain(void)
 {
-	fprintf(stderr, "Usage: ... pedit munge <MUNGE>\n");
+	fprintf(stderr, "Usage: ... pedit munge <MUNGE> [<BRANCH>]\n");
 	fprintf(stderr,
 		"Where: MUNGE := <RAW>|<LAYERED>\n"
 		"\t<RAW>:= <OFFSETC>[ATC]<CMD>\n "
@@ -47,6 +47,7 @@ explain(void)
 		"\t\tCMD:= clear | invert | set <setval>| retain\n "
 		"\t<LAYERED>:= ip <ipdata> | ip6 <ip6data> \n "
 		" \t\t| udp <udpdata> | tcp <tcpdata> | icmp <icmpdata> \n"
+		"\t<BRANCH>:= reclassify | pipe | drop | continue | pass\n"
 		"For Example usage look at the examples directory\n");
 
 }