remove data member epsilon since it only needed by constructor

src/mlpack/methods/ann/init_rules/oivs_init.hpp

@@ -64,7 +64,7 @@ class OivsInitialization
   OivsInitialization(const double epsilon = 0.1,
                      const int k = 5,
                      const double gamma = 0.9) :
-      epsilon(epsilon), k(k), gamma(gamma),
+      k(k), gamma(gamma),
       b(std::abs(ActivationFunction::inv(1 - epsilon) -
                  ActivationFunction::inv(epsilon)))
   {    
@@ -108,9 +108,6 @@ class OivsInitialization
   }
 
  private:
-  //! Parameter to control the activation region.
-  const double epsilon;
-
   //! Parameter to control the activation region width.
   const int k;