LinearSolver::Summary::status -> LinearSolver::Summary::message.

And a bunch of minor lint cleanups as they showed up.

Change-Id: I430a6b05710923c72daf6a5df4dfcd16fbf44b3a
diff --git a/internal/ceres/iterative_schur_complement_solver.cc b/internal/ceres/iterative_schur_complement_solver.cc
index 4777d02..c4c77af 100644
--- a/internal/ceres/iterative_schur_complement_solver.cc
+++ b/internal/ceres/iterative_schur_complement_solver.cc
@@ -160,8 +160,8 @@
   cg_summary.termination_type = FAILURE;
 
   // TODO(sameeragarwal): Refactor preconditioners to return a more
-  // sane status.
-  cg_summary.status = "Preconditioner update failed.";
+  // sane message.
+  cg_summary.message = "Preconditioner update failed.";
   if (preconditioner_update_was_successful) {
     cg_summary = cg_solver.Solve(schur_complement_.get(),
                                  schur_complement_->rhs().data(),