xgl: fix constness of pointers
diff --git a/loader/loader.c b/loader/loader.c
index 548a9aa..e505b1a 100644
--- a/loader/loader.c
+++ b/loader/loader.c
@@ -625,7 +625,8 @@
         return loader_get_layer_env(icd, gpu_index, layerNames);
     }
 
-    XGL_LAYER_CREATE_INFO *pCi = (XGL_LAYER_CREATE_INFO *) pCreateInfo->pNext;
+    const XGL_LAYER_CREATE_INFO *pCi =
+        (const XGL_LAYER_CREATE_INFO *) pCreateInfo->pNext;
 
     while (pCi) {
         if (pCi->sType == XGL_STRUCTURE_TYPE_LAYER_CREATE_INFO) {