coverity 12606 Logically dead code
The previous fix (commit 325abca7135d06225adf5380d726de60dacda5a4)
for "Ticket #303 - make DNA range requests work with transactions"
introduced this dead code. Since dna_pre_op does not allocate
an entry "e", there is no need to check the flag "free_entry" and
Reviewed by email@example.com (Thanks, Mark!!).