Renamed dhcp app directory name.

Change-Id: I50548db3dd6fe04a351797b34dc7560d3dff7f06
diff --git a/apps/pom.xml b/apps/pom.xml
index 3cbc905..e5ceddd 100644
--- a/apps/pom.xml
+++ b/apps/pom.xml
@@ -57,7 +57,7 @@
         <module>vtnrsc</module>
         <module>vtn</module>
         <module>vtnweb</module>
-        <module>onos-app-dhcp</module>
+        <module>dhcp</module>
     </modules>
 
     <properties>