Fix a compilation warning in autodiff_manifold.h

Change-Id: Iff6c57fb68752440eedb5b1eedc33fd524a19de2

include/ceres/autodiff_manifold.h

diff --git a/include/ceres/autodiff_manifold.h b/include/ceres/autodiff_manifold.h
index fb5f459..b2f5c9d 100644
--- a/include/ceres/autodiff_manifold.h
+++ b/include/ceres/autodiff_manifold.h
@@ -224,7 +224,7 @@
   return internal::AutoDifferentiate<
       kAmbientSize,
       internal::StaticParameterDims<kAmbientSize, kTangentSize>>(
-      internal::PlusWrapper(*functor_),
+      internal::PlusWrapper<Functor>(*functor_),
       parameter_ptrs,
       kAmbientSize,
       x_plus_delta,
@@ -247,7 +247,7 @@
   return internal::AutoDifferentiate<
       kTangentSize,
       internal::StaticParameterDims<kAmbientSize, kAmbientSize>>(
-      internal::MinusWrapper(*functor_),
+      internal::MinusWrapper<Functor>(*functor_),
       parameter_ptrs,
       kAmbientSize,
       y_minus_x,