AddOnManager: remove useless traces

These were acceptable in media kit log, but are only annoying now that
the AddOnManager is ran in applications. Moreover, these get to stdout
and make some WebKit tests fail.

src/kits/media/AddOnManager.cpp

@@ -278,9 +278,6 @@ AddOnManager::_RegisterAddOn(const entry_ref& ref)
 {
 	BPath path(&ref);
 
-	printf("AddOnManager::_RegisterAddOn(): trying to load \"%s\"\n",
-		path.Path());
-
 	ImageLoader loader(path);
 	status_t status = loader.InitCheck();
 	if (status != B_OK)
@@ -424,8 +421,6 @@ AddOnManager::_RegisterDecoder(DecoderPlugin* plugin, const entry_ref& ref)
 		}
 	}
 
-	printf("AddOnManager::_RegisterDecoder, name %s\n", ref.name);
-
 	decoder_info info;
 	info.ref = ref;