tests: having one NewRandomBlankDataVolume() is enough
tests: having one NewRandomBlankDataVolume() is enough

Signed-off-by: Dan Kenigsberg <184831158ae7531bcabc22617ed51e8717c81e93@redhat.com>

kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt,kubevirt/kubevirt