Fix compilation

src/libtomahawk/Source.cpp

@@ -477,7 +477,8 @@ Source::playlistInterface()
     return m_playlistInterface;
 }
 
-QSharedPointer<QMutex> Source::acquireLock()
+QSharedPointer<QMutexLocker>
+Source::acquireLock()
 {
     return QSharedPointer<QMutexLocker>( new QMutexLocker( &m_mutex ) );
 }

src/libtomahawk/Source.h

@@ -102,7 +102,7 @@ public:
 
     Tomahawk::playlistinterface_ptr playlistInterface();
 
-    QSharedPointer<QMutex> acquireLock();
+    QSharedPointer<QMutexLocker> acquireLock();
 
 signals:
     void syncedWithDatabase();