test: add OSMO_SOCKADDR_STR_FMT to sockaddr_str_test.c

This shows the weird format choice for showing IPv6 addresses' port, fixed in
subsequent patch.

Change-Id: I8e5ebfbbc3a2b88aed820e8f845d9f6ededb29de
diff --git a/tests/sockaddr_str/sockaddr_str_test.c b/tests/sockaddr_str/sockaddr_str_test.c
index 4284387..bf7d738 100644
--- a/tests/sockaddr_str/sockaddr_str_test.c
+++ b/tests/sockaddr_str/sockaddr_str_test.c
@@ -107,6 +107,8 @@
 		printf("\n\n");
 		dump_oip(x);
 
+		printf("  OSMO_SOCKADDR_STR_FMT: '" OSMO_SOCKADDR_STR_FMT "'\n",
+		       OSMO_SOCKADDR_STR_FMT_ARGS(x));
 		printf("  osmo_sockaddr_str_is_set() = %s\n", osmo_sockaddr_str_is_set(x) ? "true" : "false");
 		printf("  osmo_sockaddr_str_is_nonzero() = %s\n", osmo_sockaddr_str_is_nonzero(x) ? "true" : "false");