ANW: fix my fix for a file descriptor leak

Change-Id: Ief7b973fbdb76920abed19707963a0c3d306af31
diff --git a/include/system/window.h b/include/system/window.h
index 1e7f114..1c168db 100644
--- a/include/system/window.h
+++ b/include/system/window.h
@@ -830,7 +830,7 @@
         err = sync_wait(fenceFd, UINT_MAX);
         close(fenceFd);
         if (err != 0) {
-            anw->cancelBuffer(anw, *anb, fenceFd);
+            anw->cancelBuffer(anw, *anb, -1);
             *anb = NULL;
         }
     }