Low: libcrmcommon: Always free temp node in mark_child_deleted()

This takes the ACL regression test trace outputs back to the state
before the previous commit. The issue was that when candidate (the temp
node) couldn't be freed due to ACL denial, it remained in the new XML
and was processed as a newly created node (recursively).

Signed-off-by: Reid Wahl <nrwahl@protonmail.com>