Some code cleanup for GCC 4.x
diff --git a/drivers/lan91c96.h b/drivers/lan91c96.h
index b7d7455..7d33a82 100644
--- a/drivers/lan91c96.h
+++ b/drivers/lan91c96.h
@@ -51,7 +51,7 @@
  * in order to override the default mac address.
  */
 
-void smc_set_mac_addr(const char *addr);
+void smc_set_mac_addr(const unsigned char *addr);
 
 
 /* I want some simple types */