remove extra spinning from mpsc parker

Author: ibraheemdev

library/std/src/sync/mpmc/context.rs

@@ -115,21 +115,6 @@ impl Context {
     /// If the deadline is reached, `Selected::Aborted` will be selected.
     #[inline]
     pub fn wait_until(&self, deadline: Option<Instant>) -> Selected {
-        // Spin for a short time, waiting until an operation is selected.
-        let backoff = Backoff::new();
-        loop {
-            let sel = Selected::from(self.inner.select.load(Ordering::Acquire));
-            if sel != Selected::Waiting {
-                return sel;
-            }
-
-            if backoff.is_completed() {
-                break;
-            } else {
-                backoff.snooze();
-            }
-        }
-
         loop {
             // Check whether an operation has been selected.
             let sel = Selected::from(self.inner.select.load(Ordering::Acquire));