This flag now means "image was opened", while the "empty image"
concept makes this always true. Since there's one user of this
flag, which is obviously incorrect, remove the latter and fix
the former to mean "at least one object was read".
Reviewed-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>