Fix build on 32-bit and 64-bit Windows


git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@5051 3789f03b-4d11-0410-bbf8-ca57d06f2519
diff --git a/vncviewer/CConn.h b/vncviewer/CConn.h
index e48b3c7..24fbbab 100644
--- a/vncviewer/CConn.h
+++ b/vncviewer/CConn.h
@@ -40,7 +40,7 @@
   void blockCallback();
 
   // Callback when socket is ready (or broken)
-  static void socketEvent(int fd, void *data);
+  static void socketEvent(FL_SOCKET fd, void *data);
 
   // CConnection callback methods
   void serverInit();