basictest/test.rb: update message

* basictest/test.rb (test_check): update the file name in
  messages, as r53537.  [Feature #11982]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53539 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

basictest/test.rb

@@ -105,7 +105,7 @@ def test_check(what)
   unless $ntest.zero?
     PROGRESS.finish
   end
-  STDERR.print "sample/test.rb:#{what} "
+  STDERR.print "basictest/test.rb:#{what} "
   PROGRESS.init
   $what = what
   $testnum = 0