Fixed a warning.

Transform::Identity() is now returning a Transform.

Eigen/src/Geometry/Transform.h

@@ -345,9 +345,14 @@ public:
 
   /** \sa MatrixBase::setIdentity() */
   void setIdentity() { m_matrix.setIdentity(); }
-  static const typename MatrixType::IdentityReturnType Identity()
+
+  /**
+   * \brief Returns an identity transformation.
+   * \todo In the future this function should be returning a Transform expression.
+   */
+  static const Transform Identity()
   {
-    return MatrixType::Identity();
+    return Transform(MatrixType::Identity());
   }
 
   template<typename OtherDerived>