elif replace if
elif replace if

3 'if' at same levels and each 'if' has 'return',
in this case, elif is better than if.
more readable, more effective.

Change-Id: Ib0528ab69679f320f1580971945ce36eaaedf011
Signed-off-by: peiy <6553e2612b41ac7c7431ca6ace28213c0bfbafbe@rc.inesa.com>

ChameleonCloud/horizon,ChameleonCloud/horizon,NeCTAR-RC/horizon,NeCTAR-RC/horizon,openstack/horizon,openstack/horizon,openstack/horizon,NeCTAR-RC/horizon,noironetworks/horizon,openstack/horizon,ChameleonCloud/horizon,NeCTAR-RC/horizon,ChameleonCloud/horizon,noironetworks/horizon,noironetworks/horizon,noironetworks/horizon