Fix Uninitialized argument value

examples/core/core_3d_picking.c

@@ -30,7 +30,7 @@ int main()
     Vector3 cubePosition = { 0.0f, 1.0f, 0.0f };
     Vector3 cubeSize = { 2.0f, 2.0f, 2.0f };
 
-    Ray ray;        // Picking line ray
+    Ray ray = {0.0f, 0.0f, 0.0f};        // Picking line ray
 
     bool collision = false;
 
@@ -79,7 +79,6 @@ int main()
                 }
 
                 DrawRay(ray, MAROON);
-                
                 DrawGrid(10, 1.0f);
 
             End3dMode();