a21248f storage_backend_rbd: remove unnessary translated message marker

1 file Authored by Chen Hanxiao 7 years ago, Committed by John Ferlan 7 years ago,
    storage_backend_rbd: remove unnessary translated message marker
    
    Remove unnessary translated message marker _()
    for the VIR_WARN messages.
    
    Signed-off-by: Chen Hanxiao <chenhanxiao@gmail.com>