Check error returned from retry.Config.Run()

provisioner/powershell/provisioner.go

@@ -254,7 +254,7 @@ func (p *Provisioner) Provision(ctx context.Context, ui packer.Ui, comm packer.C
 		// that the upload succeeded, a restart is initiated, and then the
 		// command is executed but the file doesn't exist any longer.
 		var cmd *packer.RemoteCmd
-		retry.Config{StartTimeout: p.config.StartRetryTimeout}.Run(ctx, func(ctx context.Context) error {
+		err = retry.Config{StartTimeout: p.config.StartRetryTimeout}.Run(ctx, func(ctx context.Context) error {
 			if _, err := f.Seek(0, 0); err != nil {
 				return err
 			}