Use `&.` instead of modifier if and remove needless closed?

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@63631 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/test_tempfile.rb

@@ -361,7 +361,7 @@ puts Tempfile.new('foo').path
     f.close
     assert_file.exist?(path)
   ensure
-    f.close if f && !f.closed?
+    f&.close
     File.unlink path if path
   end