Update src/com/codefortomorrow/advanced/chapter16/solutions/LinkedList.java

Co-authored-by: Rebecca Dang <35876322+phrdang@users.noreply.github.com>

Author: armeetj

src/com/codefortomorrow/advanced/chapter16/solutions/LinkedList.java

@@ -114,6 +114,7 @@ public String toString() {
             current = current.getNext();
         } while (current != null);
 
+        // Remove trailing comma and space after last list element
         list = list.substring(0, list.length() - 2);
         return list + "]";
     }