dm snapshot: drop unused last_percent

The last_percent field is unused - remove it.
(It dates from when events were triggered as each X% filled up.)
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

drivers/md/dm-snap.c

@@ -600,7 +600,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 
 	s->valid = 1;
 	s->active = 0;
-	s->last_percent = 0;
 	init_rwsem(&s->lock);
 	spin_lock_init(&s->pe_lock);
 	s->ti = ti;

drivers/md/dm-snap.h

@@ -158,9 +158,6 @@ struct dm_snapshot {
 	/* Used for display of table */
 	char type;
 
-	/* The last percentage we notified */
-	int last_percent;
-
 	mempool_t *pending_pool;
 
 	struct exception_table pending;