wait for shutdown command to end so we get stderr/out

builder/vmware/common/step_shutdown.go

@@ -57,6 +57,11 @@ func (s *StepShutdown) Run(state multistep.StateBag) multistep.StepAction {
 			return multistep.ActionHalt
 		}
 
+		// Wait for the command to run so we can print std{err,out}
+		// We don't care if the command errored, since we'll notice
+		// if the vm didn't shut down.
+		cmd.Wait()
+
 		log.Printf("Shutdown stdout: %s", stdout.String())
 		log.Printf("Shutdown stderr: %s", stderr.String())