No need to declare 'display' here.

unix/xserver/hw/vnc/XserverDesktop.cc

@@ -49,8 +49,6 @@ extern "C" {
 #define public c_public
 #define class c_class
 
-extern const char *display;
-
 #ifdef RANDR
 #include "randrstr.h"
 #endif

unix/xserver/hw/vnc/xvnc.cc

@@ -103,7 +103,6 @@ extern "C" {
                        "See http://www.tigervnc.org for information on TigerVNC.\n")
 
 
-extern const char *display;
 extern int monitorResolution;
 
 #define VFB_DEFAULT_WIDTH  1024