Fix a link error in evaluation_benchmark.cc

Change-Id: I82ab8adc9c53e14ea2bd2398b978b41f60cca7d7

internal/ceres/evaluation_benchmark.cc

diff --git a/internal/ceres/evaluation_benchmark.cc b/internal/ceres/evaluation_benchmark.cc
index e08e113..d089f9b 100644
--- a/internal/ceres/evaluation_benchmark.cc
+++ b/internal/ceres/evaluation_benchmark.cc
@@ -85,7 +85,7 @@
 
     auto jacobian = evaluator->CreateJacobian();
     auto block_sparse = downcast_unique_ptr<BlockSparseMatrix>(jacobian);
-    CHECK_NE(block_sparse.get(), nullptr);
+    CHECK(block_sparse != nullptr);
 
     std::mt19937 rng;
     std::normal_distribution<double> rnorm;