Fix getting instance events on subsequent attempts

When the code for getting the list of events for a given instance
was moved into the InstanceEvents object, an indenting error was
introduced, which causes the get method to return None instead of
the list if the instance already has some events waiting.

This corrects that issue.

Closes-bug: #1296808
Change-Id: I099a605980dd9c2ae0659b82c633caeb8a19bbe9
Open Juno development

Bump preversion to 2014.2 to formally open Juno development.
The Icehouse release branch (milestone-proposed) will be cut
from the last commit before this one.

Change-Id: I9b6ed32059a6428dcdd20258c7aaf966c61d5962
Merge commit 'refs/changes/38/84138/2' of git://gold.eng.hq.xensource.com/git/github/openstack/nova into tmpbranch