ProgressFolder shouldn't finish progress bars on completion

ProgressFolders represent only a part of the whole iterator and
so shouldn't finish progress bars as they don't have knowledge
of the completion of the rest of folders and otherwise could
prematurely finish a progress bar

src/rayon.rs

@@ -180,9 +180,6 @@ impl<T, C: Folder<T>> Folder<T> for ProgressFolder<C> {
     }
 
     fn complete(self) -> C::Result {
-        if !self.progress.is_finished() {
-            self.progress.finish_using_style();
-        }
         self.base.complete()
     }