Fix dox at internal::tridiagonal_qr_step

Eigen/src/Eigenvalues/SelfAdjointEigenSolver.h

diff --git a/Eigen/src/Eigenvalues/SelfAdjointEigenSolver.h b/Eigen/src/Eigenvalues/SelfAdjointEigenSolver.h
index d10eba2..fc8ecaa 100644
--- a/Eigen/src/Eigenvalues/SelfAdjointEigenSolver.h
+++ b/Eigen/src/Eigenvalues/SelfAdjointEigenSolver.h
@@ -355,6 +355,7 @@
     bool m_eigenvectorsOk;
 };
 
+namespace internal {
 /** \internal
   *
   * \eigenvalues_module \ingroup Eigenvalues_Module
@@ -371,7 +372,6 @@
   * Implemented from Golub's "Matrix Computations", algorithm 8.3.2:
   * "implicit symmetric QR step with Wilkinson shift"
   */
-namespace internal {
 template<int StorageOrder,typename RealScalar, typename Scalar, typename Index>
 EIGEN_DEVICE_FUNC
 static void tridiagonal_qr_step(RealScalar* diag, RealScalar* subdiag, Index start, Index end, Scalar* matrixQ, Index n);