This reverts commit d4485423.

Should fix a crash reported by the bugreport ml.

audioscrobbler: *Never* do module unloading from within the module. You are basically unloading the code you are executing, that's a nice crasher.

Also make sure playlist is not NULL. (This is an attempt to fix a from the famous bugreport ml).

The audio output locking rule seems very vague. Moreover there could be some cross lock issues.

Spotted in our bugreport ml.

The check was stupid (always was). This seems way more logical.