visual: removes warnings about unused parameters in vlc callback and Run() functions

modules/visualization/visual/effects.c

@@ -45,6 +45,8 @@
 int dummy_Run( visual_effect_t * p_effect, aout_instance_t *p_aout,
                aout_buffer_t * p_buffer , picture_t * p_picture)
 {
+    VLC_UNUSED(p_effect); VLC_UNUSED(p_aout); VLC_UNUSED(p_buffer);
+    VLC_UNUSED(p_picture);
     return 0;
 }
 
@@ -786,6 +788,7 @@ int spectrometer_Run(visual_effect_t * p_effect, aout_instance_t *p_aout,
 int scope_Run(visual_effect_t * p_effect, aout_instance_t *p_aout,
               aout_buffer_t * p_buffer , picture_t * p_picture)
 {
+    VLC_UNUSED(p_aout);
     int i_index;
     float *p_sample ;
     uint8_t *ppp_area[2][3];

modules/visualization/visual/visual.c

@@ -424,6 +424,8 @@ static int FilterCallback( vlc_object_t *p_this, char const *psz_cmd,
                            vlc_value_t oldval, vlc_value_t newval,
                            void *p_data )
 {
+    VLC_UNUSED(psz_cmd); VLC_UNUSED(oldval);
+    VLC_UNUSED(p_data); VLC_UNUSED(newval);
     aout_filter_t     *p_filter = (aout_filter_t *)p_this;
     /* restart this baby */
     msg_Dbg( p_filter, "we should restart the visual filter" );