CID 316508: Insecure data handling (TAINTED_SCALAR)

*** CID 316508:  Insecure data handling  (TAINTED_SCALAR)
/lib/dns/journal.c: 1714 in dns_journal_iter_init()
1708     
1709     			result = journal_next(j, &pos);
1710     			if (result == ISC_R_NOMORE) {
1711     				result = ISC_R_SUCCESS;
1712     			}
1713     			CHECK(result);
>>>     CID 316508:  Insecure data handling  (TAINTED_SCALAR)
>>>     Using tainted variable "pos.serial" as a loop boundary.
1714     		} while (pos.serial != end_serial);
1715     
1716     		/*
1717     		 * For each RR, subtract the length of the RR header,
1718     		 * as this would not be present in IXFR messages.
1719     		 * (We don't need to worry about the transaction header