tests: get test name from testing.T (#22941)

There were 2 TODOs about that fix after Golang 1.8 release.
It's here for 3 years already, so now should be the right time.

tests/transaction_test.go

@@ -47,7 +47,7 @@ func TestTransaction(t *testing.T) {
 	txt.skipLoad("^ttValue/TransactionWithHighValueOverflow.json")
 	txt.walk(t, transactionTestDir, func(t *testing.T, name string, test *TransactionTest) {
 		cfg := params.MainnetChainConfig
-		if err := txt.checkFailure(t, name, test.Run(cfg)); err != nil {
+		if err := txt.checkFailure(t, test.Run(cfg)); err != nil {
 			t.Error(err)
 		}
 	})