Remove legacy keycodes, part 3 (#18669)

* `KC__VOLDOWN` -> `KC_VOLD`

* `KC__VOLUP` -> `KC_VOLU`

* `KC__MUTE` -> `KC_MUTE`

* `KC_POWER` -> `KC_PWR`

keyboards/v4n4g0rth0n/v2/keymaps/default/keymap.c

@@ -43,10 +43,10 @@ void matrix_scan_user(void){
             // Reset moving to 0 so that we don't get multiple attempts to do this
             int num_ticks = ((float)pot_val/max_pot_val)*max_ticks;
             for (int i = 0; i<max_ticks;++i){
-                tap_code(KC__VOLDOWN);
+                tap_code(KC_VOLD);
             }
             for (int i = 0; i<num_ticks;++i){
-                tap_code(KC__VOLUP);
+                tap_code(KC_VOLU);
             }
             moving = false;
         }