WORD64 compile fix. This bug catched on a overview of the code.

The code is wrong since the first git revision, so it seens that it has
not been compiled with WORD64 for quite some time, there is also another
interesting code in xkb/XKBRdBuf.c:
  <hash>ifdef WORD64
  _XkbWriteCopyData32 Not Implemented Yet for sizeof(int)==8
  <hash>endif
and possibly there are other similar problems.

src/XlibInt.c

@@ -3213,7 +3213,7 @@ static doData32(
 void _XData32(
     Display *dpy,
     long *data,
-    unsigned len,
+    unsigned len)
 {
     char packbuffer[PACKBUFFERSIZE];
     unsigned nunits = PACKBUFFERSIZE >> 2;