mount: remove extra calls of mntns_collect_root()

Now mntns_collect_root() should be called each time when we need to get
a root of a specified namespace and we don't need to call it for
initializing the global variable.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

cr-restore.c

@@ -1251,9 +1251,6 @@ static int restore_task_with_children(void *_arg)
 		if (close_old_fds(current))
 			exit(1);
 
-		if (mntns_collect_root(getpid()) < 0)
-			exit(1);
-
 		if (root_prepare_shared())
 			goto err;
 	}

mount.c

@@ -828,9 +828,6 @@ struct mount_info *collect_mntinfo(struct ns_id *ns)
 {
 	struct mount_info *pm;
 
-	if (mntns_collect_root(ns->pid) < 0)
-		return NULL;
-
 	pm = parse_mountinfo(ns->pid, ns);
 	if (!pm) {
 		pr_err("Can't parse %d's mountinfo\n", ns->pid);