Change to task::Context in docs for oneshot

Author: MajorBreakfast

futures-channel/src/oneshot.rs

@@ -403,7 +403,7 @@ impl<T> Receiver<T> {
 
     /// Attempts to receive a message outside of the context of a task.
     ///
-    /// Useful when a [`Context`](Context) is not available
+    /// Useful when a [`Context`](task::Context) is not available
     /// such as within a `Drop` impl.
     ///
     /// Does not schedule a task wakeup or have any other side effects.