1. Fix uninitialized use of pr in cr_dedup_one_pagemap and get_page:
https://github.com/xemul/criu/issues/178
2. In ud_open, close pr in case of error returned from find_vmas->
collect_uffd_pages as we free lpi with lpi->pr open; so need check in
lpi_fini if uffd is >0 before close

v2:rebase to new criu-dev
Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>