Fix an erroneous namespace comment

Change-Id: Ie1b0b75e1638fbbe0309455e1b4e6229dbdd841c

internal/ceres/tiny_solver_autodiff_function_test.cc

diff --git a/internal/ceres/tiny_solver_autodiff_function_test.cc b/internal/ceres/tiny_solver_autodiff_function_test.cc
index de4f953..7b54c0f 100644
--- a/internal/ceres/tiny_solver_autodiff_function_test.cc
+++ b/internal/ceres/tiny_solver_autodiff_function_test.cc
@@ -95,4 +95,5 @@
   EXPECT_NEAR(4.0, jacobian(1, 1), kTolerance);
   EXPECT_NEAR(6.0, jacobian(1, 2), kTolerance);
 }
-}  // namespace tinysolver
+
+}  // namespace ceres

internal/ceres/tiny_solver_test.cc

diff --git a/internal/ceres/tiny_solver_test.cc b/internal/ceres/tiny_solver_test.cc
index f92b186..df0101f 100644
--- a/internal/ceres/tiny_solver_test.cc
+++ b/internal/ceres/tiny_solver_test.cc
@@ -192,4 +192,4 @@
   TestHelper(f, x0);
 }
 
-}  // namespace tinysolver
+}  // namespace ceres