Merge pull request #14372 from bas-vk/bootnodegenkey

cmd/bootnode: stop after generating/writing nodekey

cmd/bootnode/main.go

@@ -68,6 +68,7 @@ func main() {
 		if err = crypto.SaveECDSA(*genKey, nodeKey); err != nil {
 			utils.Fatalf("%v", err)
 		}
+		return
 	case *nodeKeyFile == "" && *nodeKeyHex == "":
 		utils.Fatalf("Use -nodekey or -nodekeyhex to specify a private key")
 	case *nodeKeyFile != "" && *nodeKeyHex != "":