minor: Remove some mono compiler warnings in OpenSim.Framework.dll

OpenSim/Framework/Util.cs

@@ -303,12 +303,12 @@ namespace OpenSim.Framework
         // Clamp the maximum magnitude of a vector
         public static Vector3 ClampV(Vector3 x, float max)
         {
-            Vector3 ret = x;
             float lenSq = x.LengthSquared();
             if (lenSq > (max * max))
             {
                 x = x / x.Length() * max;
             }
+
             return x;
         }