core/rawdb: better error message in freezer (ethereum#23901)

* core/rawdb: better error message in freezer

* Apply suggestions from code review

Author: holiman

core/rawdb/freezer_batch.go

@@ -116,7 +116,7 @@ func (batch *freezerTableBatch) reset() {
 // existing data.
 func (batch *freezerTableBatch) Append(item uint64, data interface{}) error {
 	if item != batch.curItem {
-		return errOutOrderInsertion
+		return fmt.Errorf("%w: have %d want %d", errOutOrderInsertion, item, batch.curItem)
 	}
 
 	// Encode the item.
@@ -136,7 +136,7 @@ func (batch *freezerTableBatch) Append(item uint64, data interface{}) error {
 // existing data.
 func (batch *freezerTableBatch) AppendRaw(item uint64, blob []byte) error {
 	if item != batch.curItem {
-		return errOutOrderInsertion
+		return fmt.Errorf("%w: have %d want %d", errOutOrderInsertion, item, batch.curItem)
 	}
 
 	encItem := blob

core/rawdb/freezer_test.go

@@ -246,7 +246,7 @@ func TestFreezerConcurrentModifyTruncate(t *testing.T) {
 		if truncateErr != nil {
 			t.Fatal("concurrent truncate failed:", err)
 		}
-		if !(modifyErr == nil || modifyErr == errOutOrderInsertion) {
+		if !(errors.Is(modifyErr, nil) || errors.Is(modifyErr, errOutOrderInsertion)) {
 			t.Fatal("wrong error from concurrent modify:", modifyErr)
 		}
 		checkAncientCount(t, f, "test", 10)