HPCC-12697 Fix warnings reported as errors with gcc 4.4

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #6726 from ghalliday/issue12697

HPCC-12697 Fix warnings reported as errors with gcc 4.4

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>