lntemp+lntest: use t.Cleanup to register cleanup functions

lntest/itest/lnd_channel_backup_test.go

@@ -401,8 +401,7 @@ func testChannelBackupRestoreBasic(ht *lntemp.HarnessTest) {
 	for _, testCase := range testCases {
 		tc := testCase
 		success := ht.Run(tc.name, func(t *testing.T) {
-			h, cleanup := ht.Subtest(t)
-			defer cleanup()
+			h := ht.Subtest(t)
 
 			runChanRestoreScenarioBasic(h, tc.restoreMethod)
 		})
@@ -445,17 +444,15 @@ func testChannelBackupRestoreUnconfirmed(ht *lntemp.HarnessTest) {
 	// Use the channel backup file that contains an unconfirmed channel and
 	// make sure recovery works as well.
 	ht.Run("restore unconfirmed channel file", func(t *testing.T) {
-		st, cleanup := ht.Subtest(t)
+		st := ht.Subtest(t)
 		runChanRestoreScenarioUnConfirmed(st, true)
-		cleanup()
 	})
 
 	// Create a backup using RPC that contains an unconfirmed channel and
 	// make sure recovery works as well.
 	ht.Run("restore unconfirmed channel RPC", func(t *testing.T) {
-		st, cleanup := ht.Subtest(t)
+		st := ht.Subtest(t)
 		runChanRestoreScenarioUnConfirmed(st, false)
-		cleanup()
 	})
 }
 
@@ -568,8 +565,7 @@ func testChannelBackupRestoreCommitTypes(ht *lntemp.HarnessTest) {
 	for _, testCase := range testCases {
 		tc := testCase
 		success := ht.Run(tc.name, func(t *testing.T) {
-			h, cleanup := ht.Subtest(t)
-			defer cleanup()
+			h := ht.Subtest(t)
 
 			runChanRestoreScenarioCommitTypes(
 				h, tc.ct, tc.zeroConf,
@@ -671,17 +667,15 @@ func testChannelBackupRestoreForceClose(ht *lntemp.HarnessTest) {
 	// Restore a channel that was force closed by dave just before going
 	// offline.
 	ht.Run("from backup file anchors", func(t *testing.T) {
-		st, cleanup := ht.Subtest(t)
+		st := ht.Subtest(t)
 		runChanRestoreScenarioForceClose(st, false)
-		cleanup()
 	})
 
 	// Restore a zero-conf anchors channel that was force closed by dave
 	// just before going offline.
 	ht.Run("from backup file anchors w/ zero-conf", func(t *testing.T) {
-		st, cleanup := ht.Subtest(t)
+		st := ht.Subtest(t)
 		runChanRestoreScenarioForceClose(st, true)
-		cleanup()
 	})
 }
 

lntest/itest/lnd_funding_test.go

@@ -127,8 +127,7 @@ test:
 				"carol_commit=%v,dave_commit=%v", cc, dc,
 			)
 			success := ht.Run(testName, func(t *testing.T) {
-				st, cleanup := ht.Subtest(t)
-				defer cleanup()
+				st := ht.Subtest(t)
 				testFunding(st, cc, dc)
 			})
 

lntest/itest/lnd_multi-hop_test.go

@@ -171,8 +171,7 @@ func runMultiHopHtlcClaimTest(ht *lntemp.HarnessTest, tester caseRunner) {
 		}
 
 		s := ht.Run(name, func(t1 *testing.T) {
-			st, cleanup := ht.Subtest(t1)
-			defer cleanup()
+			st := ht.Subtest(t1)
 
 			alice := st.NewNode("Alice", args)
 			bob := st.NewNode("Bob", args)

lntest/itest/temp_lnd_test.go

@@ -94,8 +94,7 @@ func TestLightningNetworkDaemonTemp(t *testing.T) {
 			// Create a separate harness test for the testcase to
 			// avoid overwriting the external harness test that is
 			// tied to the parent test.
-			ht, cleanup := harnessTest.Subtest(t1)
-			defer cleanup()
+			ht := harnessTest.Subtest(t1)
 
 			// TODO(yy): split log files.
 			cleanTestCaseName := strings.ReplaceAll(