Fix data race,ref #4857

Signed-off-by: v01dstar <[email protected]>

server/cluster/unsafe_recovery_controller_test.go

@@ -1316,17 +1316,17 @@ func (s *testUnsafeRecoverySuite) TestRemoveFailedStores(c *C) {
 func (s *testUnsafeRecoverySuite) TestSplitPaused(c *C) {
 	_, opt, _ := newTestScheduleConfig()
 	cluster := newTestRaftCluster(s.ctx, mockid.NewIDAllocator(), opt, storage.NewStorageWithMemoryBackend(), core.NewBasicCluster())
+	recoveryController := newUnsafeRecoveryController(cluster)
+	cluster.Lock()
+	cluster.unsafeRecoveryController = recoveryController
 	cluster.coordinator = newCoordinator(s.ctx, cluster, hbstream.NewTestHeartbeatStreams(s.ctx, cluster.meta.GetId(), cluster, true))
+	cluster.Unlock()
 	cluster.coordinator.run()
 	stores := newTestStores(2, "5.3.0")
 	stores[1] = stores[1].Clone(core.SetLastHeartbeatTS(time.Now()))
 	for _, store := range stores {
 		c.Assert(cluster.PutStore(store.GetMeta()), IsNil)
 	}
-	recoveryController := newUnsafeRecoveryController(cluster)
-	cluster.Lock()
-	cluster.unsafeRecoveryController = recoveryController
-	cluster.Unlock()
 	failedStores := map[uint64]struct{}{
 		1: {},
 	}