lxd/daemon/storage: Skip unmounting LVM pools in daemonStorageUnmount
lxd/daemon/storage: Skip unmounting LVM pools in daemonStorageUnmount

Temporary fix to work around issues with LVM tests caused by 7be090d1df0c44970a2e5454e0f413e760aac078

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

stgraber/lxd,hallyn/lxd,hallyn/lxd,atxwebs/lxd,lxc/lxd,lxc/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,atxwebs/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,atxwebs/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,atxwebs/lxd,lxc/lxd