Puppet plugin: return a more explicit operatingsystem name

Previously, we merely returned 'oVirt'. Now, strip out spaces from
the parsed result in order to match the expected return from other
Puppet operating systems.

Change-Id: I73be03ef369d023bb94a33d81e6cb90e0a0f976b
Signed-off-by: Ryan Barry <rbarry@redhat.com>