Support building with -Werror=strict-prototypes / -Werror=old-style-definition

Unfortunately "-std=c99" is not sufficient to make gcc ignore code that
uses constructs of earlier C standards, which were abandoned in C99.

See https://lwn.net/ml/fedora-devel/Y1kvF35WozzGBpc8@redhat.com/ for
some related discussion.

Change-Id: I861be39275b40c522c02f553074c5a4489e87127
diff --git a/tests/mslookup/mslookup_client_test.c b/tests/mslookup/mslookup_client_test.c
index 9fcb983..84b7810 100644
--- a/tests/mslookup/mslookup_client_test.c
+++ b/tests/mslookup/mslookup_client_test.c
@@ -147,7 +147,7 @@
 	osmo_timers_update(); \
 } while (0)
 
-static void fake_time_start()
+static void fake_time_start(void)
 {
 	struct timespec *clock_override;
 
@@ -169,7 +169,7 @@
 	LOGP(DMSLOOKUP, LOGL_DEBUG, "result_cb(): %s\n", osmo_mslookup_result_name_c(ctx, query, result));
 }
 
-int main()
+int main(int argc, char **argv)
 {
 	ctx = talloc_named_const(NULL, 0, "main");
 	osmo_init_logging2(ctx, NULL);