clippy: Fix abs_diff warning

Author: dcz

src/utils/serial.rs

@@ -22,11 +22,7 @@ impl Eq for Serial {}
 impl PartialOrd for Serial {
     #[inline]
     fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        let distance = if self.0 > other.0 {
-            self.0 - other.0
-        } else {
-            other.0 - self.0
-        };
+        let distance = self.0.abs_diff(other.0);
         if distance < u32::MAX / 2 {
             self.0.partial_cmp(&other.0)
         } else {