Adds console logging to swift-drive-audit

This patch adds console logging ability to swift-drive-audit.
There are cases where logging to console is necessary when drive-audit
is done. This can be consumed for flagging errors in monitoring tools
such as icinga.

DocImpact
Change-Id: Ia1e1effcbd89bd2cf6d5b8c64019f1647c736a3a
Merge "Adds console logging to swift-drive-audit"