vnc: avoid write only variables

Compiling with GCC 4.6.0 20100925 produced warnings:
/src/qemu/ui/vnc.c: In function 'vnc_client_cache_auth':
/src/qemu/ui/vnc.c:217:12: error: variable 'qdict' set but not used [-Werror=unused-but-set-variable]
/src/qemu/ui/vnc.c: In function 'vnc_display_open':
/src/qemu/ui/vnc.c:2526:9: error: variable 'acl' set but not used [-Werror=unused-but-set-variable]

Fix by making the variable declarations and their uses also conditional
to debug definition.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

ui/vnc.c

diff --git a/ui/vnc.c b/ui/vnc.c
index c7a1831..864342e 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -214,13 +214,17 @@
 
 static void vnc_client_cache_auth(VncState *client)
 {
+#if defined(CONFIG_VNC_TLS) || defined(CONFIG_VNC_SASL)
     QDict *qdict;
+#endif
 
     if (!client->info) {
         return;
     }
 
+#if defined(CONFIG_VNC_TLS) || defined(CONFIG_VNC_SASL)
     qdict = qobject_to_qdict(client->info);
+#endif
 
 #ifdef CONFIG_VNC_TLS
     if (client->tls.session &&
@@ -2523,7 +2527,9 @@
     int sasl = 0;
     int saslErr;
 #endif
+#if defined(CONFIG_VNC_TLS) || defined(CONFIG_VNC_SASL)
     int acl = 0;
+#endif
     int lock_key_sync = 1;
 
     if (!vnc_display)
@@ -2581,8 +2587,10 @@
                 return -1;
             }
 #endif
+#if defined(CONFIG_VNC_TLS) || defined(CONFIG_VNC_SASL)
         } else if (strncmp(options, "acl", 3) == 0) {
             acl = 1;
+#endif
         } else if (strncmp(options, "lossy", 5) == 0) {
             vs->lossy = true;
         }