Fix a few build warnings

Author: ids1024

src/backend/wayland/buffer.rs

@@ -84,7 +84,7 @@ impl AppData {
             return Ok(None);
         };
         let drm_dev = drm_dev.unwrap_or(feedback.main_device() as u64);
-        let Some((dev_path, gbm)) = self.gbm_devices.gbm_device(drm_dev)? else {
+        let Some((_dev_path, gbm)) = self.gbm_devices.gbm_device(drm_dev)? else {
             return Ok(None);
         };
         let formats = feedback.format_table();

src/main.rs

@@ -792,11 +792,11 @@ impl Application for App {
         iced::Subscription::batch(subscriptions)
     }
 
-    fn view(&self) -> cosmic::prelude::Element<Self::Message> {
+    fn view(&self) -> cosmic::Element<'_, Self::Message> {
         unreachable!()
     }
 
-    fn view_window(&self, id: iced::window::Id) -> cosmic::prelude::Element<Self::Message> {
+    fn view_window(&self, id: iced::window::Id) -> cosmic::Element<'_, Self::Message> {
         if let Some(surface) = self.layer_surfaces.get(&id) {
             return view::layer_surface(self, surface);
         }

src/widgets/toplevels/toplevel_layout/row_col_toplevel_layout.rs

@@ -68,7 +68,6 @@ impl AxisToplevelLayout for RowColToplevelLayout {
         max_limit: AxisSize,
         toplevels: &[LayoutToplevel<'_, AxisSize>],
     ) -> impl Iterator<Item = AxisRectangle> {
-        let requested_main_total = self.requested_main_total(toplevels);
         let scale_factor = self.scale_factor(max_limit, toplevels);
 
         // Add padding to center if total requested size doesn't fill available space