fix memory leak by closing batches in batchRows()

index/firestorm/firestorm.go

@@ -194,6 +194,9 @@ func (f *Firestorm) batchRows(writer store.KVWriter, rowsOfRows [][]index.IndexR
 
 	// prepare batch
 	wb := writer.NewBatch()
+	defer func() {
+		_ = wb.Close()
+	}()
 
 	var kbuf []byte
 	var vbuf []byte

index/upside_down/upside_down.go

@@ -139,6 +139,9 @@ func (udc *UpsideDownCouch) batchRows(writer store.KVWriter, addRows []UpsideDow
 
 	// prepare batch
 	wb := writer.NewBatch()
+	defer func() {
+		_ = wb.Close()
+	}()
 
 	// buffer to work with
 	rowBuf := GetRowBuffer()