Fix a memory leak in trust_region_minimizer_test.cc

Change-Id: I46dff90485a8106c154cbd72493acda64971e94a

internal/ceres/trust_region_minimizer_test.cc

diff --git a/internal/ceres/trust_region_minimizer_test.cc b/internal/ceres/trust_region_minimizer_test.cc
index 9d5af1a..a82dea7 100644
--- a/internal/ceres/trust_region_minimizer_test.cc
+++ b/internal/ceres/trust_region_minimizer_test.cc
@@ -366,6 +366,10 @@
   Solver::Summary summary;
   Solve(options, &problem, &summary);
   EXPECT_LE(summary.final_cost, 1e-10);
+
+  for (int i = 0; i < N; i++) {
+    delete y[i];
+  }
 }
 
 }  // namespace internal