wifi: Only use the static WifiInformationElement method to deserialize optional IEs

src/wifi/model/wifi-information-element.h

@@ -259,17 +259,6 @@ public:
    * \return an iterator
    */
   Buffer::Iterator Deserialize (Buffer::Iterator i);
-  /**
-   * Deserialize entire IE if it is present. The iterator passed in
-   * must be pointing at the Element ID of an information element. If
-   * the Element ID is not the one that the given class is interested
-   * in then it will return the same iterator.
-   *
-   * \param i an iterator which points to where the IE should be read.
-   *
-   * \return an iterator
-   */
-  Buffer::Iterator DeserializeIfPresent (Buffer::Iterator i);
   /**
    * Deserialize an IE that is optionally present. The iterator passed in
    * must be pointing at the Element ID of an information element. If
@@ -337,6 +326,17 @@ public:
   virtual bool operator== (WifiInformationElement const & a) const;
 
 private:
+  /**
+   * Deserialize entire IE if it is present. The iterator passed in
+   * must be pointing at the Element ID of an information element. If
+   * the Element ID is not the one that the given class is interested
+   * in then it will return the same iterator.
+   *
+   * \param i an iterator which points to where the IE should be read.
+   *
+   * \return an iterator
+   */
+  Buffer::Iterator DeserializeIfPresent (Buffer::Iterator i);
   /**
    * Serialize information (i.e., the body of the IE, not including
    * the Element ID and length octets)