libgtpnl: tools: gtp-tunnel: display teid in hexadecimal

So it is displayed like in wireshark.
diff --git a/tools/gtp-tunnel.c b/tools/gtp-tunnel.c
index 4980825..763ce53 100644
--- a/tools/gtp-tunnel.c
+++ b/tools/gtp-tunnel.c
@@ -148,7 +148,7 @@
 	}
 
 	printf("version %u ", pdp.version);
-	printf("tid %llu ms_addr %s ", pdp.tid, inet_ntoa(pdp.ms_addr));
+	printf("tid %llx ms_addr %s ", pdp.tid, inet_ntoa(pdp.ms_addr));
 	printf("sgsn_addr %s\n", inet_ntoa(pdp.sgsn_addr));
 
 	return MNL_CB_OK;