Apply nightly clippy suggestions/fixes (#7794)

* Reduce the diff for https://github.com/emilk/egui/pull/7793

crates/egui/src/containers/panel.rs

@@ -255,9 +255,7 @@ impl<'a> PanelSizer<'a> {
         let side = self.panel.side;
         let size_range = self.panel.size_range;
 
-        if is_resizing && pointer.is_some() {
-            let pointer = pointer.unwrap();
-
+        if is_resizing && let Some(pointer) = pointer {
             match side {
                 PanelSide::Vertical(side) => {
                     self.size = (pointer.x - side.side_x(self.panel_rect)).abs();
@@ -811,9 +809,7 @@ impl Panel {
         let resize_id = self.id.with("__resize");
         let resize_response = ui.ctx().read_response(resize_id);
 
-        if resize_response.is_some() {
-            let resize_response = resize_response.unwrap();
-
+        if let Some(resize_response) = resize_response {
             // NOTE(sharky98): The original code was initializing to
             // false first, but it doesn't seem necessary.
             let is_resizing = resize_response.dragged();

crates/egui/src/input_state/mod.rs

@@ -631,8 +631,10 @@ impl InputState {
     /// A positive Y-value indicates the content is being moved down, as when swiping down on a touch-screen or track-pad with natural scrolling.
     #[inline(always)]
     pub fn translation_delta(&self) -> Vec2 {
-        self.multi_touch()
-            .map_or(self.smooth_scroll_delta(), |touch| touch.translation_delta)
+        self.multi_touch().map_or_else(
+            || self.smooth_scroll_delta(),
+            |touch| touch.translation_delta,
+        )
     }
 
     /// True if there is an active scroll action that might scroll more when using [`Self::smooth_scroll_delta`].