lazy-pages: don't close page-read for child processes

The page-read for child process is a shallow copy of the parent process
page-read. They share the open file descriptors and the pagemap.
The lpi_fini of the child processes should not release any resources, they
all will be released during lpi_fini of the parent process.

Fixes: #325
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>

criu/uffd.c

@@ -130,14 +130,13 @@ static void free_lazy_iovs(struct lazy_pages_info *lpi)
 
 static void lpi_fini(struct lazy_pages_info *lpi)
 {
-
 	if (!lpi)
 		return;
 	free(lpi->buf);
 	free_lazy_iovs(lpi);
 	if (lpi->lpfd.fd > 0)
 		close(lpi->lpfd.fd);
-	if (lpi->pr.close)
+	if (!lpi->parent && lpi->pr.close)
 		lpi->pr.close(&lpi->pr);
 	free(lpi);
 }