Fix a type bug in more_garbow_hillstrom.cc.

Change-Id: Ia830db6cdfd15b8e90d7a3655eeab8cf6a463817

examples/more_garbow_hillstrom.cc

diff --git a/examples/more_garbow_hillstrom.cc b/examples/more_garbow_hillstrom.cc
index b93e772..03ecb9a 100644
--- a/examples/more_garbow_hillstrom.cc
+++ b/examples/more_garbow_hillstrom.cc
@@ -58,7 +58,7 @@
 namespace ceres {
 namespace examples {
 
-const int kDoubleMax = std::numeric_limits<double>::max();
+const double kDoubleMax = std::numeric_limits<double>::max();
 
 #define BEGIN_MGH_PROBLEM(name, num_parameters, num_residuals)          \
   struct name {                                                         \