There’s something mildly sadistic about a master-filmmaker botching his own, brilliant, film with an underwhelming ending, such as that which Sergei Loznitsa did with “Krotkaya” (“A gentle creature” in the Russian original). A woman whose husband is in prison gets the care package she’d sent to her husband returned to her. A delivery attempt was made, person is no longer at that jail cell. In want of news she sets off