builder/qemu: fix tests

builder/qemu/step_run.go

@@ -81,7 +81,7 @@ func getCommandArgs(bootDrive string, state multistep.StateBag) ([]string, error
 	defaultArgs["-name"] = vmName
 	defaultArgs["-machine"] = fmt.Sprintf("type=%s", config.MachineType)
 	defaultArgs["-netdev"] = fmt.Sprintf(
-		"user,id=user.0,hostfwd=tcp::%v-:%d", sshHostPort, config.SSHPort)
+		"user,id=user.0,hostfwd=tcp::%v-:%d", sshHostPort, config.Comm.Port())
 	defaultArgs["-device"] = fmt.Sprintf("%s,netdev=user.0", config.NetDevice)
 	defaultArgs["-drive"] = fmt.Sprintf("file=%s,if=%s,cache=%s,discard=%s", imgPath, config.DiskInterface, config.DiskCache, config.DiskDiscard)
 	if !config.DiskImage {