RR(XS): This JdbReadTwiceTest.sh gets an exit 1

[Dmitry Samersoff]

Hi Everyone,

Please review.

http://cr.openjdk.java.net/~dsamersoff/JDK-8002116/webrev.01/

I can't reproduce the issue locally, but suspect, the test failed
because after chmod a-r the file is sill readable. So check it
explicitly before run the test itself.

-- 
Dmitry Samersoff
Oracle Java development team, Saint Petersburg, Russia
* I would love to change the world, but they won't give me the sources.