intel: register a special XGE for each X window

Present events are delivered to the target windows.  We cannot register a
special XGE for the root window and expect things to work.
diff --git a/icd/intel/fence.c b/icd/intel/fence.c
index 5db0558..8534b10 100644
--- a/icd/intel/fence.c
+++ b/icd/intel/fence.c
@@ -73,7 +73,8 @@
     if (fence->x11) {
         const bool wait = (timeout_ns != 0);
 
-        return intel_wsi_x11_wait(fence->x11, fence->x11_serial, wait);
+        return intel_wsi_x11_wait(fence->x11, fence->x11_win,
+                fence->x11_serial, wait);
     }
 #endif