Fix build: -Wreorder, test fail

Change-Id: I7e032a9017470612fe233c3eecd51c37020dee64

internal/ceres/preconditioner.h

diff --git a/internal/ceres/preconditioner.h b/internal/ceres/preconditioner.h
index 5d293b8..d0b7a47 100644
--- a/internal/ceres/preconditioner.h
+++ b/internal/ceres/preconditioner.h
@@ -51,8 +51,8 @@
         : type(JACOBI),
           visibility_clustering_type(CANONICAL_VIEWS),
           sparse_linear_algebra_library_type(SUITE_SPARSE),
-          use_postordering(false),
           subset_preconditioner_start_row_block(-1),
+          use_postordering(false),
           num_threads(1),
           row_block_size(Eigen::Dynamic),
           e_block_size(Eigen::Dynamic),

internal/ceres/subset_preconditioner_test.cc

diff --git a/internal/ceres/subset_preconditioner_test.cc b/internal/ceres/subset_preconditioner_test.cc
index 63dbbaf..0f4cc6c 100644
--- a/internal/ceres/subset_preconditioner_test.cc
+++ b/internal/ceres/subset_preconditioner_test.cc
@@ -182,7 +182,7 @@
                         ParamInfoToString);
 #endif
 
-#ifndef CERES_NO_EIGEN_SPARSE
+#ifdef CERES_USE_EIGEN_SPARSE
 INSTANTIATE_TEST_CASE_P(SubsetPreconditionerWithEigenSparse,
                         SubsetPreconditionerTest,
                         ::testing::Combine(::testing::Values(EIGEN_SPARSE),