Fix missing return value warning.

Review by: spoon@google.com

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@7968 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/dev/core/super/com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/Util.java b/dev/core/super/com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/Util.java
index cdd0c53..facd2b8 100644
--- a/dev/core/super/com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/Util.java
+++ b/dev/core/super/com/google/gwt/dev/jjs/intrinsic/com/google/gwt/lang/Util.java
@@ -31,7 +31,7 @@
     return o.@java.lang.Object::typeMarker;
   }-*/;
 
-  static native int setTypeId(Object o, int typeId) /*-{
+  static native void setTypeId(Object o, int typeId) /*-{
     o.@java.lang.Object::typeId = typeId;
   }-*/;