Apply review edits to cinder log file section

This patch applies the edits suggested by reviewers for the other
service log patches, specifically
https://review.openstack.org/#/c/76752/ and
https://review.openstack.org/#/c/76747/.

Change-Id: I7ffb66b4c5d1974b703a4f76e5759c6f786c91e3
Related-Bug: #1282882
Merge "Apply review edits to cinder log file section"