Adding line to modify previous pointer in case of deleting a node in …

…doubly linked list.

data-structures/doubly-linked-list/doubly-linked-list.js

@@ -162,6 +162,7 @@ DoublyLinkedList.prototype = {
 
                 //skip over the item to remove
                 current.prev.next = current.next;
+                current.next.prev = current.prev;
             }
 
             //decrement the length