spdif: Use aout_FifoPop() which checks locking and fix a aout_FifoPop() leak.

Pointed-out-by a warning.

modules/audio_mixer/spdif.c

@@ -81,30 +81,19 @@ static void DoWork( aout_instance_t * p_aout, aout_buffer_t * p_buffer )
     int i = 0;
     aout_input_t * p_input = p_aout->pp_inputs[i];
     while ( p_input->b_error || p_input->b_paused )
-    {
         p_input = p_aout->pp_inputs[++i];
-    }
-    aout_FifoPop( p_aout, &p_input->fifo );
+
+    aout_buffer_t * p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo );
+    aout_BufferFree( p_old_buffer );
 
     /* Empty other FIFOs to avoid a memory leak. */
     for ( i++; i < p_aout->i_nb_inputs; i++ )
     {
-        aout_fifo_t * p_fifo;
-        aout_buffer_t * p_deleted;
-
         p_input = p_aout->pp_inputs[i];
         if ( p_input->b_error || p_input->b_paused )
             continue;
-        p_fifo = &p_input->fifo;
-        p_deleted = p_fifo->p_first;
-        while ( p_deleted != NULL )
-        {
-            aout_buffer_t * p_next = p_deleted->p_next;
-            aout_BufferFree( p_deleted );
-            p_deleted = p_next;
-        }
-        p_fifo->p_first = NULL;
-        p_fifo->pp_last = &p_fifo->p_first;
+        while ((p_old_buffer = aout_FifoPop( p_aout, &p_input->fifo )))
+            aout_BufferFree( p_old_buffer );
     }
 }