Made the PSSmRenderer stop to create a new matrix for each split on every frame

git-svn-id: https://jmonkeyengine.googlecode.com/svn/trunk@9931 75d07b2b-3a1a-0410-a2c5-0572b91ccdca

engine/src/core/com/jme3/shadow/PssmShadowRenderer.java

@@ -422,7 +422,7 @@ public class PssmShadowRenderer implements SceneProcessor {
             ShadowUtil.updateShadowCamera(occluders, receivers, shadowCam, points, splitOccluders);
 
             //saving light view projection matrix for this split            
-            lightViewProjectionsMatrices[i] = shadowCam.getViewProjectionMatrix().clone();
+            lightViewProjectionsMatrices[i].set(shadowCam.getViewProjectionMatrix());
             renderManager.setCamera(shadowCam, false);
 
             r.setFrameBuffer(shadowFB[i]);