dlm: change lock time stamping

Use ktime instead of jiffies for timestamping lkb's.  Also stamp the
time on every lkb whenever it's added to a resource queue, instead of
just stamping locks subject to timeouts.  This will allow us to use
timestamps more widely for debugging all locks.

Signed-off-by: David Teigland <teigland@redhat.com>

fs/dlm/dlm_internal.h

@@ -245,7 +245,7 @@ struct dlm_lkb {
 	struct list_head	lkb_astqueue;	/* need ast to be sent */
 	struct list_head	lkb_ownqueue;	/* list of locks for a process */
 	struct list_head	lkb_time_list;
-	unsigned long		lkb_timestamp;
+	ktime_t			lkb_timestamp;
 	unsigned long		lkb_timeout_cs;
 
 	char			*lkb_lvbptr;