Qt4: remove useless checks

An input thread always has a valid input item even if it is dead.
If not, the code would have had a ToCToU bug anyway.

modules/gui/qt4/components/playlist/playlist_model.cpp

@@ -563,7 +563,7 @@ void PLModel::processInputItemUpdate( )
     input_thread_t *p_input = THEMIM->getInput();
     if( !p_input ) return;
 
-    if( p_input && !( p_input->b_dead || !vlc_object_alive( p_input ) ) )
+    if( p_input )
     {
         PLItem *item = findByInputId( rootItem, input_GetItem( p_input )->i_id );
         if( item ) emit currentIndexChanged( index( item, 0 ) );