dump: use a virtual pid in names of zombie's core files

All per task images contains a virtual pid.
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-dump.c

@@ -1291,7 +1291,7 @@ static int dump_one_zombie(const struct pstree_item *item,
 	core->tc->task_state = TASK_DEAD;
 	core->tc->exit_code = pps->exit_code;
 
-	fd_core = open_image(CR_FD_CORE, O_DUMP, item->pid);
+	fd_core = open_image(CR_FD_CORE, O_DUMP, item->pid.virt);
 	if (fd_core < 0)
 		goto err_free;