Update glog path

Change-Id: I47a69cb267c71a9f8f3350c4f645e8cf83e44cc9
diff --git a/internal/ceres/dense_sparse_matrix.cc b/internal/ceres/dense_sparse_matrix.cc
index 9d58031..f94b888 100644
--- a/internal/ceres/dense_sparse_matrix.cc
+++ b/internal/ceres/dense_sparse_matrix.cc
@@ -35,6 +35,7 @@
 #include "ceres/triplet_sparse_matrix.h"
 #include "ceres/internal/eigen.h"
 #include "ceres/internal/port.h"
+#include "glog/logging.h"
 
 namespace ceres {
 namespace internal {