Fixes bug #1043999
simple_tenant_usage returns the usage in the range between the supplied
start and end query parameters. The _hours_for() method calculates the
number of hours the instance was running in this range, even if the end time
is in the future.
By default, python-novaclient requests usage between 4 weeks ago and tomorrow.
This means we a report which accounts for 24 hours of extra running time for
each currently running instance. Fix this by clamping the period of the
returned report at the current time.
Change-Id: I61c211fd85b729aaeaac6ef24644ee19eb5bb6b0
(cherry picked from commit 869443f41c)
4ac2dcc36b