skins2: remove unneeded brittle hack to avoid callback loop

A more proper fix was made in 3567c033.

modules/gui/skins2/vars/volume.cpp

@@ -46,15 +46,9 @@ Volume::Volume( intf_thread_t *pIntf ): VarPercent( pIntf )
 
 void Volume::set( float percentage, bool updateVLC )
 {
-    // Avoid looping forever...
-    if( (int)(get() * AOUT_VOLUME_MAX) !=
-        (int)(percentage * AOUT_VOLUME_MAX) )
-    {
     VarPercent::set( percentage );
     if( updateVLC )
-            aout_VolumeSet( getIntf()->p_sys->p_playlist,
-                            (int)(get() * m_volumeMax) );
-    }
+        aout_VolumeSet( getIntf()->p_sys->p_playlist, get() * m_volumeMax );
 }