6f8680a coverity 12563 Read from pointer after free (fix 2)

Authored and Committed by nkinder 10 years ago
    coverity 12563 Read from pointer after free (fix 2)
    
    The previous commit for coverity issue 12563 fixed the dna_pre_op()
    function to avoid reading the target of a freed pointer.  This same
    fix needs to be made to dna_be_txn_pre_op().