use osmo_init_logging2() with proper talloc ctx

Since the logging allocations now also show up in the root context report, some
tests need adjusted talloc checks.

In msc_vlr_tests, also output the number of talloc blocks before tests are
started to show that the number didn't change after the tests.

Change-Id: Iae07ae60230c7bab28e52b5df97fa3844778158e
diff --git a/tests/smpp/smpp_test.c b/tests/smpp/smpp_test.c
index 4a3af49..1abb63b 100644
--- a/tests/smpp/smpp_test.c
+++ b/tests/smpp/smpp_test.c
@@ -77,7 +77,8 @@
 
 int main(int argc, char **argv)
 {
-	osmo_init_logging(&log_info);
+	void *ctx = talloc_named_const(NULL, 0, "smpp_test");
+	osmo_init_logging2(ctx, &log_info);
 	log_set_use_color(osmo_stderr_target, 0);
 	log_set_print_filename(osmo_stderr_target, 0);