Fix removal of usage records

Author: vishesh92

engine/schema/src/main/java/com/cloud/usage/dao/UsageDaoImpl.java

@@ -476,16 +476,11 @@ public void doInTransactionWithoutResult(TransactionStatus status) {
                 TransactionLegacy txn = TransactionLegacy.currentTxn();
                 PreparedStatement pstmt = null;
                 try {
-                    txn.start();
                     pstmt = txn.prepareAutoCloseStatement(DELETE_ALL_BY_INTERVAL);
                     pstmt.setLong(1, days);
                     pstmt.executeUpdate();
-                    txn.commit();
                 } catch (Exception ex) {
-                    txn.rollback();
                     s_logger.error("error removing old cloud_usage records for interval: " + days);
-                } finally {
-                    txn.close();
                 }
             }
         });