Fix panic caused by unitialized mutex in longhorn
Fix panic caused by unitialized mutex in longhorn

rancher/rancher-volume,rancher/convoy,rancherio/rancher-volume,rancher/rancher-volume,rancherio/rancher-volume,rancher/convoy,jinuxstyle/convoy,rancher/convoy,rancherio/volmgr,rancher/rancher-volume,medallia/convoy,nickvanw/convoy,rancherio/rancher-volume,jinuxstyle/convoy,medallia/convoy,nickvanw/convoy,nickvanw/convoy,medallia/convoy,jinuxstyle/convoy,rancherio/volmgr,rancherio/volmgr