sysctl_net_802.c: Protect sysctl_tr_rif_timeout usage with CONFIG_TR.

net/802/sysctl_net_802.c

@@ -14,9 +14,12 @@
 #include <linux/sysctl.h>
 #include <linux/config.h>
 
+#ifdef CONFIG_TR
 extern int sysctl_tr_rif_timeout;
+#endif
 
 struct ctl_table tr_table[] = {
+#ifdef CONFIG_TR
 	{
 		.ctl_name	= NET_TR_RIF_TIMEOUT,
 		.procname	= "rif_timeout",
@@ -25,5 +28,6 @@ struct ctl_table tr_table[] = {
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec
 	},
+#endif /* CONFIG_TR */
 	{ 0 },
 };