winit-x11: fix debug mode overflow panic in set_timestamp

Fixes #4484

src/changelog/unreleased.md

@@ -44,3 +44,4 @@ changelog entry.
 
 - On macOS, fixed crash when dragging non-file content onto window.
 - On X11, fix `set_hittest` not working on some window managers.
+- On X11, fix debug mode overflow panic in `set_timestamp`.

src/platform_impl/linux/x11/xdisplay.rs

@@ -234,9 +234,7 @@ impl XConnection {
         // Store the timestamp in the slot if it's greater than the last one.
         let mut last_timestamp = self.timestamp.load(Ordering::Relaxed);
         loop {
-            let wrapping_sub = |a: xproto::Timestamp, b: xproto::Timestamp| (a as i32) - (b as i32);
-
-            if wrapping_sub(timestamp, last_timestamp) <= 0 {
+            if (timestamp as i32).wrapping_sub(last_timestamp as i32) <= 0 {
                 break;
             }