fix clang warnings in some 3rd party libs

src/Mod/Robot/App/kdl_cp/chaindynparam.cpp

@@ -27,7 +27,7 @@ namespace KDL {
 
     ChainDynParam::ChainDynParam(const Chain& _chain, Vector _grav):
             chain(_chain),
-            nr(0),
+            //nr(0),
             nj(chain.getNrOfJoints()),
             ns(chain.getNrOfSegments()),
             grav(_grav),

src/Mod/Robot/App/kdl_cp/chaindynparam.hpp

@@ -55,7 +55,7 @@ namespace KDL {
 
     private:
         const Chain chain;
-	int nr;
+	//int nr;
 	unsigned int nj;
         unsigned int ns;
 	Vector grav;

src/Mod/Robot/App/kdl_cp/joint.cpp

@@ -156,6 +156,7 @@ namespace KDL {
 
   Vector Joint::JointOrigin() const
   {
+    (void)inertia; (void)damping; (void)stiffness;
     return origin;
   }