tests: Explicitly drop category from log

Let's disable category here since we don't care about its formatting here.

In any case, every test relying on logging output validation should
always explicitly state the config to avoid issues in the future if
default values change.

Change-Id: I089c0001fc75e81558c3e860827e4d434cf1eab3
Related: OS#5034
diff --git a/tests/smpp/smpp_test.c b/tests/smpp/smpp_test.c
index 1abb63b..b7df653 100644
--- a/tests/smpp/smpp_test.c
+++ b/tests/smpp/smpp_test.c
@@ -81,6 +81,8 @@
 	osmo_init_logging2(ctx, &log_info);
 	log_set_use_color(osmo_stderr_target, 0);
 	log_set_print_filename(osmo_stderr_target, 0);
+	log_set_print_category(osmo_stderr_target, 0);
+	log_set_print_category_hex(osmo_stderr_target, 0);
 
 	test_coding_scheme();
 	return EXIT_SUCCESS;