Remove unnecessary return statements in tree.rb

lib/gitlab/git/rugged_impl/tree.rb

@@ -61,9 +61,9 @@ module Gitlab
             subtree = tree_entries_from_rugged(repository, sha, tree.path, false)
 
             if subtree.count == 1 && subtree.first.dir?
-              return File.join(tree.name, rugged_flatten_tree(repository, sha, subtree.first, root_path))
+              File.join(tree.name, rugged_flatten_tree(repository, sha, subtree.first, root_path))
             else
-              return tree.name
+              tree.name
             end
           end