don't remove test results

r46180 removed dots but they express the result of tests: don't remove them.
Moreover I don't understand why `read` is still used.

http://u64.rubyci.org/~chkbuild/ruby-trunk/log/20140530T200301Z.fail.html.gz

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46279 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* test/lib/leakchecker.rb: Leak checker extracted from
  test/lib/minitest/unit.rb.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@46280 b2dd03c8-39d4-4d8f-98ff-823fe69b080e