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/dense_qr_solver.cc b/internal/ceres/dense_qr_solver.cc
index fcc87d2..f8927ae 100644
--- a/internal/ceres/dense_qr_solver.cc
+++ b/internal/ceres/dense_qr_solver.cc
@@ -109,7 +109,7 @@
                                                          work_.rows(),
                                                          work_.data(),
                                                          rhs_.data(),
-                                                         &summary.status);
+                                                         &summary.message);
   event_logger.AddEvent("Solve");
   if (summary.termination_type == TOLERANCE) {
     VectorRef(x, num_cols) = rhs_.head(num_cols);
@@ -160,7 +160,7 @@
   LinearSolver::Summary summary;
   summary.num_iterations = 1;
   summary.termination_type = TOLERANCE;
-  summary.status = "Success.";
+  summary.message = "Success.";
 
   event_logger.AddEvent("TearDown");
   return summary;