_currMiddlewareIbCount is correct ibCount for Spine

Author: bofeng-song

native/cocos/2d/renderer/Batcher2d.cpp

@@ -427,7 +427,7 @@ CC_FORCE_INLINE void Batcher2d::handleMiddlewareDraw(RenderEntity* entity, Rende
 
     // check for merge draw
     auto enableBatch = !entity->getUseLocal();
-    if (enableBatch && _currTexture == texture && _currMeshBuffer == meshBuffer && !_currEntity->getUseLocal() && material->getHash() == _currMaterial->getHash() && drawInfo->getIndexOffset() == _currDrawInfo->getIndexOffset() + _currDrawInfo->getIbCount() && layer == _currLayer) {
+    if (enableBatch && _currTexture == texture && _currMeshBuffer == meshBuffer && !_currEntity->getUseLocal() && material->getHash() == _currMaterial->getHash() && drawInfo->getIndexOffset() == _currDrawInfo->getIndexOffset() + _currMiddlewareIbCount && layer == _currLayer) {
         _currMiddlewareIbCount += drawInfo->getIbCount();
     } else {
         generateBatch(_currEntity, _currDrawInfo);