Fixed Cppcheck warnings

lib/executionpath.cpp

@@ -450,7 +450,7 @@ void ExecutionPath::checkScope(const Token *tok, std::list<ExecutionPath *> &che
         }
 
 
-        {
+        if (tok) {
             tok = check->parse(*tok, checks);
             if (checks.empty())
                 return;

lib/valueflow.cpp

@@ -655,7 +655,7 @@ static void removeValues(std::list<ValueFlow::Value> &values, const std::list<Va
         if (found)
             values.erase(it++);
         else
-            it++;
+            ++it;
     }
 }