Fix an errant double in TinySolver.

Thanks to Bogdan Burlacu for pointing this out.

Change-Id: I7a59a589c1bf919954e4905df3376e9aeb1a12d7

include/ceres/tiny_solver.h

diff --git a/include/ceres/tiny_solver.h b/include/ceres/tiny_solver.h
index 47db582..0957f78 100644
--- a/include/ceres/tiny_solver.h
+++ b/include/ceres/tiny_solver.h
@@ -282,7 +282,7 @@
         }
 
         Scalar tmp = Scalar(2 * rho - 1);
-        u = u * std::max(1 / 3., 1 - tmp * tmp * tmp);
+        u = u * std::max(Scalar(1 / 3.), 1 - tmp * tmp * tmp);
         v = 2;
         continue;
       }