YOLO see if this works

```
panic: Log in goroutine after TestWorkerUpdate has completed

goroutine 1175 [running]:
testing.(*common).logDepth(0xc00019a100, 0xc0000396a0, 0x1d, 0x3)
	/usr/local/go/src/testing/testing.go:634 +0x51a
testing.(*common).log(...)
	/usr/local/go/src/testing/testing.go:614
testing.(*common).Log(0xc00019a100, 0xc00006fb00, 0x1, 0x1)
	/usr/local/go/src/testing/testing.go:642 +0x79
github.com/docker/swarmkit/agent.(*mockTaskController).Remove(0xc00020a780, 0x13b6f40, 0xc0000b4010, 0x13b6f40, 0xc0000b4010)
	/home/circleci/.go_workspace/src/github.com/docker/swarmkit/agent/worker_test.go:604 +0x8e
github.com/docker/swarmkit/agent.reconcileTaskState.func1(0xc0004dac60)
	/home/circleci/.go_workspace/src/github.com/docker/swarmkit/agent/worker.go:270 +0x137
created by github.com/docker/swarmkit/agent.reconcileTaskState
	/home/circleci/.go_workspace/src/github.com/docker/swarmkit/agent/worker.go:313 +0x1a6f
FAIL	github.com/docker/swarmkit/agent	4.244s
make: *** [coverage] Error 1
Exited with code 2
```

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
(cherry picked from commit 42085d2)
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

agent/worker.go

@@ -257,13 +257,11 @@ func reconcileTaskState(ctx context.Context, w *worker, assignments []*api.Assig
 	}
 
 	closeManager := func(tm *taskManager) {
-		go func(tm *taskManager) {
-			defer w.closers.Done()
-			// when a task is no longer assigned, we shutdown the task manager
-			if err := tm.Close(); err != nil {
-				log.G(ctx).WithError(err).Error("error closing task manager")
-			}
-		}(tm)
+		defer w.closers.Done()
+		// when a task is no longer assigned, we shutdown the task manager
+		if err := tm.Close(); err != nil {
+			log.G(ctx).WithError(err).Error("error closing task manager")
+		}
 
 		// make an attempt at removing. this is best effort. any errors will be
 		// retried by the reaper later.