Correct path to genxdr after the change to Go1.5+ vendoring

lib/discover/localpackets.go

@@ -4,7 +4,7 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this file,
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
-//go:generate -command genxdr go run ../../Godeps/_workspace/src/github.com/calmh/xdr/cmd/genxdr/main.go
+//go:generate -command genxdr go run ../../vendor/github.com/calmh/xdr/cmd/genxdr/main.go
 //go:generate genxdr -o localpackets_xdr.go localpackets.go
 
 package discover