* tool/merger.rb: unlink temporary file explicitly.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46167 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

tool/merger.rb

@@ -255,5 +255,5 @@ else
     puts 'commit failed; try again.'
   end
 
-  f.close
+  f.close(true)
 end