Third time is the charm

Change-Id: I14b3093988b3238e3f490db5dbb282f536fb2abe
diff --git a/internal/ceres/cuda_dense_cholesky_test.cc b/internal/ceres/cuda_dense_cholesky_test.cc
index 9911d49..6a45ecf 100644
--- a/internal/ceres/cuda_dense_cholesky_test.cc
+++ b/internal/ceres/cuda_dense_cholesky_test.cc
@@ -60,6 +60,7 @@
         0,   0,   0, 1;
   // clang-format on
 
+  Vector b = Eigen::Vector4d::Ones();
   LinearSolver::Options options;
   ContextImpl context;
   options.context = &context;