v2 page-read: rework open_page_read to use in shmem restore

Signed-off-by: Tikhomirov Pavel <snorcht@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
v2 dedup: make bunched auto-deduplication on restore for shmem

in restore_shmem_content() use open_page_read() to open images

Signed-off-by: Tikhomirov Pavel <snorcht@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
v2 (v6) zdtm: test for auto-dedup on restore

if final size of all pages images is zero than dedup works

use :
bash test/zdtm.sh --auto-dedup
bash test/zdtm.sh --auto-dedup static/maps04
bash test/zdtm.sh -P -i 3 --auto-dedup -t transition/maps007

changes: aplicable for all tests, -ad changed to --auto-dedup,
simplify, check all private pages images, check shmem images
and go with shmem patch set.

Acked-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Tikhomirov Pavel <snorcht@gmail.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>