devmapper: Fix unit test
devmapper: Fix unit test

dx9/convoy,rancherio/rancher-volume,nickvanw/convoy,moypray/convoy,rancherio/volmgr,medallia/convoy,rancher/rancher-volume,mehulsbhatt/convoy,jinuxstyle/convoy,rancherio/rancher-volume,medallia/convoy,dx9/convoy,mehulsbhatt/convoy,aruneli/convoy,moypray/convoy,rancher/convoy,rancherio/volmgr,rancher/convoy,nickvanw/convoy,nickvanw/convoy,medallia/convoy,aruneli/convoy,dx9/convoy,jinuxstyle/convoy,rancherio/volmgr,jinuxstyle/convoy,rancherio/rancher-volume,mehulsbhatt/convoy,moypray/convoy,rancher/rancher-volume,rancher/rancher-volume,aruneli/convoy,rancher/convoy