ubifs: tnc: use monotonic znode timestamp

The tnc uses get_seconds() based timestamps to check the age of a znode,
which has two problems: on 32-bit architectures this may overflow in
2038 or 2106, and it gives incorrect information when the system time
is updated using settimeofday().

Using montonic timestamps with ktime_get_seconds() solves both thes
problems.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Richard Weinberger <richard@nod.at>
diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
index 04bf84d..54fb6b1 100644
--- a/fs/ubifs/ubifs.h
+++ b/fs/ubifs/ubifs.h
@@ -758,7 +758,7 @@ struct ubifs_znode {
 	struct ubifs_znode *parent;
 	struct ubifs_znode *cnext;
 	unsigned long flags;
-	unsigned long time;
+	time64_t time;
 	int level;
 	int child_cnt;
 	int iip;