Add sliver to the LRU after I/O is complete.  This way, we don't have to add the same sliver twice in a single I/O and is more logical.
Add sliver to the LRU after I/O is complete.  This way, we don't have
to add the same sliver twice in a single I/O and is more logical.

pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable,pscedu/slash2-stable