DEC Tulip: Fix the compile-breaking mistake.

src/network/net_tulip.c

@@ -452,9 +452,7 @@ tulip_copy_rx_bytes(TULIPState *s, struct tulip_descriptor *desc)
 static bool
 tulip_filter_address(TULIPState *s, const uint8_t *addr)
 {
-#ifdef BLOCK_BROADCAST
     static const char broadcast[] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
-#endif
     bool              ret         = false;
 
     for (uint8_t i = 0; i < 16 && ret == false; i++) {