Replacement `_` on `_LW` in all LOG.warning part 2

oslo.i18n uses different marker functions to separate the
translatable messages into different catalogs, which the translation
teams can prioritize translating. For details, please refer to:
http://docs.openstack.org/developer/oslo.i18n/guidelines.html#guidelines-for-use-in-openstack

There were not marker fuctions some places in directory network.
This commit makes changes:
* Add missing marker functions
* Use ',' instead of '%' while adding variables to log messages

Change-Id: I5ab13610d3e10a68ae49f9fd7fac151aa66ea98d
Merge "Replacement `_` on `_LW` in all LOG.warning part 2"