use unique feature name for std::sync::mpsc::IntoIter

Author: rapha

src/libstd/sync/mpsc/mod.rs

@@ -309,7 +309,7 @@ pub struct Iter<'a, T: 'a> {
 /// An owning iterator over messages on a receiver, this iterator will block
 /// whenever `next` is called, waiting for a new message, and `None` will be
 /// returned when the corresponding channel has hung up.
-#[stable(feature = "rust1", since = "1.1.0")]
+#[stable(feature = "rust1.1", since = "1.1.0")]
 pub struct IntoIter<T> {
     rx: Receiver<T>
 }