Revert "logging: add log level cache"

This reverts commit 7dc6d4a629a37bb081d62f6ce61f4e5ee0237247.

Reason for revert: other tests are failing

Change-Id: Ife4c49d1bb933e983ac68c57970c9c49b40e08be
diff --git a/tests/ctrl/ctrl_test.c b/tests/ctrl/ctrl_test.c
index 7b7e6ce..1d4d4d7 100644
--- a/tests/ctrl/ctrl_test.c
+++ b/tests/ctrl/ctrl_test.c
@@ -482,7 +482,7 @@
 	test_deferred_cmd();
 
 	/* Expecting root ctx + msgb root ctx + 5 logging elements */
-	if (talloc_total_blocks(ctx) != 8) {
+	if (talloc_total_blocks(ctx) != 7) {
 		talloc_report_full(ctx, stdout);
 		OSMO_ASSERT(false);
 	}