ll_types.c: optimize link type table, make it conditional
            on FEATURE_IP_RARE_PROTOCOLS

function                                             old     new   delta
static.arphrd_name                                     -     373    +373
static.arphrd_type                                     -     124    +124
ll_type_n2a                                           58      78     +20
static.arphrd_names                                  496       -    -496
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 1/0 up/down: 517/-496)           Total: 21 bytes
   text    data     bss     dec     hex filename
 776880     974    9420  787274   c034a busybox_old
 776594     974    9420  786988   c022c busybox_unstripped

diff --git a/networking/libiproute/rt_names.h b/networking/libiproute/rt_names.h
index 98c22b0..f560f24 100644
--- a/networking/libiproute/rt_names.h
+++ b/networking/libiproute/rt_names.h
@@ -22,7 +22,9 @@
 				char *buf, int blen);
 extern int ll_addr_a2n(unsigned char *lladdr, int len, char *arg);
 
+#ifdef UNUSED
 extern const char* ll_proto_n2a(unsigned short id, char *buf, int len);
 extern int ll_proto_a2n(unsigned short *id, char *buf);
+#endif
 
 #endif