Use fileutils.write_to_tempfile in LogConfigTestCase
Use fileutils.write_to_tempfile in LogConfigTestCase

There is method to create temporary file in fileutils.
we can utilize that.

Change-Id: I6bbcc82dea509d0a9ea9e831631f6c7cc0c50039

zzicewind/oslo.log,meganjbaker/oslo.log,magic0704/oslo.log,JioCloud/oslo.log,dims/oslo.log,akash1808/oslo.log,varunarya10/oslo.log,openstack/oslo.log