Use from/import style in module report

Files in module report are using 'import openstack.common.*', not 'from
openstack.common import'. Though these two ways work well. But the first
one let update.py can't replace with base_name, see
https://github.com/openstack/oslo-incubator/blob/master/update.py#L163
Considering other modules are using oslo-incubator code in the second way,
to keep consistency, we'd better follow the last one.

Closes-Bug: #1304774

Change-Id: Ife98dc96b012d6aa7b5bd10d09a733506072fa1c
Merge "Use from/import style in module report"