HPCC-12674 RoxieReleaseRow() Avoid locking decrements when possible

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
HPCC-12674 updates following review

Signed-off-by: Gavin Halliday <gavin.halliday@lexisnexis.com>
Merge pull request #6758 from ghalliday/issue12674

HPCC-12674 RoxieReleaseRow() Avoid locking decrements when possible

Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>