Fix minor code issues

src/collection/collection.cpp

@@ -168,6 +168,8 @@ void SCollection::Stopped() {
 
 void SCollection::CurrentSongChanged(const Song &song) {  // FIXME
 
+  Q_UNUSED(song);
+
   TagReaderReply *reply = nullptr;
 
   if (reply) {
@@ -177,4 +179,5 @@ void SCollection::CurrentSongChanged(const Song &song) {  // FIXME
 }
 
 void SCollection::SongsStatisticsChanged(const SongList &songs) {
+  Q_UNUSED(songs);
 }

src/collection/collectionbackend.cpp

@@ -1222,6 +1222,8 @@ void CollectionBackend::IncrementPlayCount(int id) {
 
 void CollectionBackend::IncrementSkipCount(int id, float progress) {
 
+  Q_UNUSED(progress);
+
   if (id == -1) return;
 
   QMutexLocker l(db_->Mutex());

src/collection/collectionmodel.cpp

@@ -587,6 +587,8 @@ QVariant CollectionModel::AlbumIcon(const QModelIndex &idx) {
 
 void CollectionModel::AlbumCoverLoaded(const quint64 id, const QUrl &cover_url, const QImage &image) {
 
+  Q_UNUSED(cover_url);
+
   if (!pending_art_.contains(id)) return;
 
   ItemAndCacheKey item_and_cache_key = pending_art_.take(id);

src/collection/collectionmodel.h

@@ -59,7 +59,8 @@ class CollectionItem;
 
 class CollectionModel : public SimpleTreeModel<CollectionItem> {
   Q_OBJECT
-  Q_ENUMS(GroupBy);
+
+  Q_ENUMS(GroupBy)
 
  public:
   CollectionModel(CollectionBackend *backend, Application *app, QObject *parent = nullptr);
@@ -285,7 +286,7 @@ signals:
   QSet<QString> pending_cache_keys_;
 };
 
-Q_DECLARE_METATYPE(CollectionModel::Grouping);
+Q_DECLARE_METATYPE(CollectionModel::Grouping)
 
 QDataStream &operator<<(QDataStream &s, const CollectionModel::Grouping &g);
 QDataStream &operator>>(QDataStream &s, CollectionModel::Grouping &g);