move remaining help text from include/usage.src.h

Signed-off-by: Pere Orga <gotrunks@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

networking/udhcp/dhcprelay.c

@@ -9,6 +9,12 @@
  *                   Netbeat AG
  * Upstream has GPL v2 or later
  */
+
+//usage:#define dhcprelay_trivial_usage
+//usage:       "CLIENT_IFACE[,CLIENT_IFACE2]... SERVER_IFACE [SERVER_IP]"
+//usage:#define dhcprelay_full_usage "\n\n"
+//usage:       "Relay DHCP requests between clients and server"
+
 #include "common.h"
 
 #define SERVER_PORT    67