HPCC-10844 Fix minor leak in type processing

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #5413 from ghalliday/issue10844b

HPCC-10844 Fix minor leak in type processing

Reviewed-By: Jamie Noss <james.noss@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>