[subset] Use hb_clamp instead of consequent hb_min and hb_max calls

As just a minor code tweak to clarify the intention better.

src/graph/graph.hh

@@ -368,7 +368,7 @@ struct graph_t
       // it's parent where possible.
 
       int64_t modified_distance =
-          hb_min (hb_max(distance + distance_modifier (), 0), 0x7FFFFFFFFFF);
+          hb_clamp (distance + distance_modifier (), 0, 0x7FFFFFFFFFF);
       if (has_max_priority ()) {
         modified_distance = 0;
       }

src/hb-subset-instancer-solver.cc

@@ -376,7 +376,7 @@ double renormalizeValue (double v, const Triple &triple,
   assert (lower <= def && def <= upper);
 
   if (!extrapolate)
-      v = hb_max (hb_min (v, upper), lower);
+    v = hb_clamp (v, lower, upper);
 
   if (v == def)
     return 0.0;