gprs_ns2_sns: Implement error log in case no binds found for NSE

Change-Id: I66ce4b429ad2597343b48210fdcbc95a1f34cbcd
diff --git a/src/gb/gprs_ns2_sns.c b/src/gb/gprs_ns2_sns.c
index a8baa28..715dd8e 100644
--- a/src/gb/gprs_ns2_sns.c
+++ b/src/gb/gprs_ns2_sns.c
@@ -756,7 +756,7 @@
 	/* count how many bindings are available (only UDP binds) */
 	count = llist_count(&gss->binds);
 	if (count == 0) {
-		/* TODO: logging */
+		LOGPFSML(fi, LOGL_ERROR, "No local binds for this NSE -> cannot determine IP endpoints\n");
 		return;
 	}