Description of problem:
Although the fake data are fetched from multihost environment when virt-who run at offline mode, setting is_hypervisor=False(wrong config), virt-who still send wrong host/guest mapping info to server rather than send error info in the log.

Version-Release number of selected component (if applicable):
virt-who-0.14-4.el7.noarch
subscription-manager-1.15.9-6.el7.x86_64
python-rhsm-1.15.4-2.el7.x86_64
Satellite6.1.0-20150818.1

How reproducible:
Always

Steps to Reproduce:
1. Register system to satellite
2. Generate fake data which are fetched from multihost environment and save it to /root/fake:
# cat /root/fake
{"hypervisors": [{"uuid": "88d979a3-34f8-4cca-84e8-df0988257ba6", "guests": []}, {"uuid": "2c014415-c274-40f4-8265-b99c83d3e1aa", "guests": [{"guestId": "754215b3-e01e-420f-b7a8-e0cd2972c624", "state": 1, "attributes": {"active": 1, "virtWhoType": "rhevm", "hypervisorType": "qemu"}}, {"guestId": "4f1f93b8-c4c5-424d-89d8-1822367d2274", "state": 1, "attributes": {"active": 1, "virtWhoType": "rhevm", "hypervisorType": "qemu"}}]}]}
3. Run virt-who at offline mode and set is_hypervisor=False
# cat /etc/virt-who.d/fake
[fake-virt]
type=fake
file=/root/fake
is_hypervisor=False
owner=ACME_Corporation
env=Library
4.Restart virt-who service and check virt-who's log
# tail -f /var/log/rhsm/rhsm.log
2015-08-26 17:19:02,016 [DEBUG]  @virtwho.py:126 - Using config named 'fake-virt'
2015-08-26 17:19:02,017 [INFO]  @virtwho.py:661 - Using configuration "fake-virt" ("fake" mode)
2015-08-26 17:19:02,017 [DEBUG]  @virtwho.py:209 - Starting infinite loop with 3600 seconds interval
2015-08-26 17:19:02,050 [DEBUG]  @subscriptionmanager.py:112 - Authenticating with certificate: /etc/pki/consumer/cert.pem
2015-08-26 17:19:05,623 [INFO]  @subscriptionmanager.py:136 - Sending domain info: [] 

Actual results:
virt-who send wrong mapping info to server,it just fetched guest info from the first host 

Expected results:
Since fake data are fetched from multihost environment which is not suit to is_hypervisor = False, Virt-who shouldn't send the wrong mapping info to satellite, it should show error info in the log:
" Virt backend 'fake-virt' fails with error: Fake virt file '/root/fake' is not properly formed: 'uuid' "

Additional info:
When fake data are fetched from singal host environment, setting is_hypervisor=True(Wrong config), virt-who won't send host/guest mapping to server but show error info as the following:
" Virt backend 'fake-virt' fails with error: Fake virt file '/root/fake' is not properly formed: 'uuid' "