Update src/future.rs

Co-authored-by: John Nunley <jtnunley01@gmail.com>

src/future.rs

@@ -496,16 +496,14 @@ impl<Fut: Future> Future for Fuse<Fut> {
     type Output = Fut::Output;
 
     fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Fut::Output> {
-        self.as_mut()
-            .project()
-            .inner
-            .as_pin_mut()
-            .map(|f| f.poll(cx))
-            .unwrap_or(Poll::Pending)
-            .map(|output| {
+        match self.as_mut().project().inner.as_pin_mut().map(|f| f.poll(cx)) {
+            Some(Poll::Ready(output)) => {
                 self.project().inner.set(None);
-                output
-            })
+                Poll::Ready(output)
+            }
+
+            Some(Poll::Pending) | None => Poll::Pending
+        }
     }
 }