Fix some Clang warnings

Found by Clang in extra verbose mode :-)

No functional change.

src/evaluate.cpp

@@ -78,7 +78,7 @@ namespace {
 
   public:
     Evaluation() = delete;
-    Evaluation(const Position& p) : pos(p) {};
+    Evaluation(const Position& p) : pos(p) {}
     Evaluation& operator=(const Evaluation&) = delete;
 
     Value value();