HPCC-11360 Variable file spray fails with out of disk space message

Add checking and error handling for RECFV file spray.

Signed-off-by: Attila Vamos <attila.vamos@gmail.com>
HPCC-11360 Variable file spray fails with out of disk space message

Update after review

Signed-off-by: Attila Vamos <attila.vamos@gmail.com>
Merge pull request #5878 from AttilaVamos/HPCC-11360-fix

HPCC-11360 Variable file spray fails with out of disk space message

Reviewed-By: Gavin Halliday <gavin.halliday@lexisnexis.com>
Reviewed-By: John Holt <john.d.holt@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>