Remove unnecessary destructors

Change-Id: I1d1cc9b15606955ee1d99d2f81585f118bc92aef

internal/ceres/schur_complement_solver.cc

diff --git a/internal/ceres/schur_complement_solver.cc b/internal/ceres/schur_complement_solver.cc
index 4836981..ba96e1c 100644
--- a/internal/ceres/schur_complement_solver.cc
+++ b/internal/ceres/schur_complement_solver.cc
@@ -68,8 +68,6 @@
       const BlockRandomAccessSparseMatrix& m)
       : m_(m) {}
 
-  virtual ~BlockRandomAccessSparseMatrixAdapter() {}
-
   void RightMultiplyAndAccumulate(const Vector& x, Vector& y) final {
     m_.SymmetricRightMultiplyAndAccumulate(x.data(), y.data());
   }
@@ -85,8 +83,6 @@
       const BlockRandomAccessDiagonalMatrix& m)
       : m_(m) {}
 
-  virtual ~BlockRandomAccessDiagonalMatrixAdapter() final {}
-
   // y = y + Ax;
   void RightMultiplyAndAccumulate(const Vector& x, Vector& y) final {
     m_.RightMultiplyAndAccumulate(x.data(), y.data());