Fixed trailing whitespace.

Author: ArturKovacs

src/libcore/iter/traits/iterator.rs

@@ -202,7 +202,7 @@ pub trait Iterator {
     /// Consumes the iterator, counting the number of iterations and returning it.
     ///
     /// This method will evaluate the iterator until its [`next`] returns
-    /// [`None`]. Once [`None`] is encountered, `count()` returns one less than the 
+    /// [`None`]. Once [`None`] is encountered, `count()` returns one less than the
     /// number of times it called [`next`]. Note that [`next`] has to be called at
     /// least once even if the iterator does not have any elements.
     ///