test_tmpdir.rb: remove tmpdir

* test/test_tmpdir.rb (TestTmpdir#test_no_homedir): remove created
  tmpdir.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38669 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/test_tmpdir.rb

@@ -28,5 +28,6 @@ class TestTmpdir < Test::Unit::TestCase
     assert_match(/\A~/, File.basename(dir), bug7547)
   ensure
     ENV["HOME"] = home
+    Dir.rmdir(dir) if dir
   end
 end