tools/benchmark: remove deadcode

The Execute() function is a deadcode. Let's remove it.

tools/benchmark/cmd/root.go

@@ -15,8 +15,6 @@
 package cmd
 
 import (
-	"fmt"
-	"os"
 	"sync"
 
 	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/cheggaaa/pb"
@@ -48,10 +46,3 @@ func init() {
 	RootCmd.PersistentFlags().UintVar(&totalConns, "conns", 1, "Total number of gRPC connections")
 	RootCmd.PersistentFlags().UintVar(&totalClients, "clients", 1, "Total number of gRPC clients")
 }
-
-func Execute() {
-	if err := RootCmd.Execute(); err != nil {
-		fmt.Println(err)
-		os.Exit(-1)
-	}
-}