dm persistent data: remove redundant value_size arg from value_ptr

Now that the value_size is held within every node of the btrees we can
remove this argument from value_ptr().

For the last few months a BUG_ON has been checking this argument is
the same as that held in the node.  No issues were reported.  So this
is a safe change.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/persistent-data/dm-btree-internal.h b/drivers/md/persistent-data/dm-btree-internal.h
index d279c76..5709bfe 100644
--- a/drivers/md/persistent-data/dm-btree-internal.h
+++ b/drivers/md/persistent-data/dm-btree-internal.h
@@ -108,12 +108,9 @@
 	return &n->keys[le32_to_cpu(n->header.max_entries)];
 }
 
-/*
- * FIXME: Now that value size is stored in node we don't need the third parm.
- */
-static inline void *value_ptr(struct node *n, uint32_t index, size_t value_size)
+static inline void *value_ptr(struct node *n, uint32_t index)
 {
-	BUG_ON(value_size != le32_to_cpu(n->header.value_size));
+	uint32_t value_size = le32_to_cpu(n->header.value_size);
 	return value_base(n) + (value_size * index);
 }