Fixed an unused param warning

libnetutils had a single warning. Fixed it to make it clean.

Change-Id: I9297e556657a38dbdd7d1d0ac4bc3574801d5ac9
Author: Edwin Vane <edwin.vane@intel.com>
Reviewed-by: Kevin P Schoedel <kevin.p.schoedel@intel.com>
diff --git a/libnetutils/packet.c b/libnetutils/packet.c
index 3ec83fe..be4e0db 100644
--- a/libnetutils/packet.c
+++ b/libnetutils/packet.c
@@ -39,7 +39,7 @@
 
 int fatal();
 
-int open_raw_socket(const char *ifname, uint8_t *hwaddr, int if_index)
+int open_raw_socket(const char *ifname __attribute__((unused)), uint8_t *hwaddr, int if_index)
 {
     int s, flag;
     struct sockaddr_ll bindaddr;