fix compiler warnings in modules/video_output/fb.c

modules/video_output/fb.c

@@ -466,6 +466,7 @@ static int NewPicture( vout_thread_t *p_vout, picture_t *p_pic )
  *****************************************************************************/
 static void FreePicture( vout_thread_t *p_vout, picture_t *p_pic )
 {
+    VLC_UNUSED(p_vout);
     free( p_pic->p_sys->p_data );
     free( p_pic->p_sys );
     p_pic->p_sys = NULL;
@@ -978,6 +979,7 @@ static void CloseDisplay( vout_thread_t *p_vout )
  *****************************************************************************/
 static void SwitchDisplay( int i_signal )
 {
+    VLC_UNUSED( i_signal );
 #if 0
     vout_thread_t *p_vout;