Doc: Fix build warnings for missing code-block lang
Doc: Fix build warnings for missing code-block lang

These should specify "none" or a language.

Change-Id: I0e4ec78c417cdb1efed5c76ee39d16c4e362750f

j-griffith/cinder,phenoxim/cinder,ge0rgi/cinder,openstack/cinder,phenoxim/cinder,j-griffith/cinder,mahak/cinder,eharney/cinder,Datera/cinder,Datera/cinder,eharney/cinder,openstack/cinder,mahak/cinder