better comments and remove commented code

nomad/deploymentwatcher/deployment_watcher.go

@@ -406,6 +406,10 @@ FAIL:
 			if !next.Equal(currentDeadline) {
 				prevDeadlineZero := currentDeadline.IsZero()
 				currentDeadline = next
+				// The most recent deadline can be zero if no allocs were created for this deployment.
+				// The deadline timer would have already been stopped once in that case. To prevent
+				// deadlocking on the already stopped deadline timer, we only drain the channel if
+				// the previous deadline was not zero.
 				if !prevDeadlineZero && !deadlineTimer.Stop() {
 					<-deadlineTimer.C
 				}

nomad/deploymentwatcher/deployments_watcher_test.go

@@ -899,10 +899,7 @@ func TestDeploymentWatcher_Watch_StartWithoutProgressDeadline(t *testing.T) {
 	a := mock.Alloc()
 	a.CreateTime = time.Now().UnixNano()
 	a.DeploymentID = d.ID
-	/*a.DeploymentStatus = &structs.AllocDeploymentStatus{
-		Healthy:   helper.BoolToPtr(false),
-		Timestamp: time.Now(),
-	}*/
+
 	assert.Nil(m.state.UpsertAllocs(m.nextIndex(), []*structs.Allocation{a}), "UpsertAllocs")
 
 	d.TaskGroups["web"].ProgressDeadline = 500 * time.Millisecond