use osmo_init_logging2() with proper talloc ctx

Ironically, when deprecating osmo_init_logging() in
I216837780e9405fdaec8059c63d10699c695b360, I forgot to change the callers
within libosmocore itself, i.e. in the various regression tests.

Change-Id: Ia36c248f99353d5baaa2533f46a2f60a8579bdf8
diff --git a/tests/gb/gprs_bssgp_test.c b/tests/gb/gprs_bssgp_test.c
index c38e180..52e986e 100644
--- a/tests/gb/gprs_bssgp_test.c
+++ b/tests/gb/gprs_bssgp_test.c
@@ -294,11 +294,14 @@
 int main(int argc, char **argv)
 {
 	struct sockaddr_in bss_peer= {0};
+	void *ctx = talloc_named_const(NULL, 0, "gprs_bssgp_test");
 
-	osmo_init_logging(&info);
+	osmo_init_logging2(ctx, &info);
 	log_set_use_color(osmo_stderr_target, 0);
 	log_set_print_filename(osmo_stderr_target, 0);
 
+	msgb_talloc_ctx_init(ctx, 0);
+
 	bssgp_nsi = gprs_ns_instantiate(gprs_ns_callback, NULL);
 
 	bss_peer.sin_family = AF_INET;