Remove unused find_attribute_or_element()
Remove unused find_attribute_or_element()

find_attribute_or_element() is not used since the first commit
(c53d8e343e50d4cf7ea9a6a81258848c2d893bfb), then this patch removes
the method.

Change-Id: I3429860e7b1eb983b994b5c1c16caff1fef066ff

winndows/cinder,phenoxim/cinder,scottdangelo/RemoveVolumeMangerLocks,eharney/cinder,Paul-Ezell/cinder-1,openstack/cinder,potsmaster/cinder,JioCloud/cinder,ge0rgi/cinder,eharney/cinder,nikesh-mahalka/cinder,CloudServer/cinder,NetApp/cinder,duhzecca/cinder,petrutlucian94/cinder,tlakshman26/cinder-https-changes,saeki-masaki/cinder,tlakshman26/cinder-bug-fix-volume-conversion-full,tlakshman26/cinder-https-changes,bswartz/cinder,nexusriot/cinder,sasukeh/cinder,nikesh-mahalka/cinder,scottdangelo/RemoveVolumeMangerLocks,potsmaster/cinder,Nexenta/cinder,tlakshman26/cinder-new-branch,bswartz/cinder,dims/cinder,nexusriot/cinder,JioCloud/cinder,NetApp/cinder,apporc/cinder,saeki-masaki/cinder,mahak/cinder,CloudServer/cinder,winndows/cinder,duhzecca/cinder,Nexenta/cinder,leilihh/cinder,mahak/cinder,Hybrid-Cloud/cinder,petrutlucian94/cinder,phenoxim/cinder,cloudbase/cinder,openstack/cinder,j-griffith/cinder,scality/cinder,Datera/cinder,Hybrid-Cloud/cinder,scality/cinder,leilihh/cinder,tlakshman26/cinder-bug-fix-volume-conversion-full,Paul-Ezell/cinder-1,sasukeh/cinder,Datera/cinder,takeshineshiro/cinder,manojhirway/ExistingImagesOnNFS,apporc/cinder,dims/cinder,takeshineshiro/cinder,tlakshman26/cinder-new-branch,cloudbase/cinder,j-griffith/cinder,manojhirway/ExistingImagesOnNFS