Fix for rhbz769731 - HA LVM failure to remove tag thwarts service relocation
    
    A change in the behaviour of handling missing PVs by LVM has necessitated
    an update to the HA LVM scripts.  Without the update, a failed PV remains
    in the VG until it is removed via 'vgreduce'.  Since no updates to the metadata
    can happen while the VG is in this state, the "tags" used by HA LVM cannot be
    removed and relocation cannot take place.