RFR: 8178867: tools/jlink/multireleasejar/JLinkMultiReleaseJarTest.java failed to clean up files

[Andrey Nazarov]

Hi,

Please review fix in Jlink test. The fix is to close the Stream which works 
with a file system.

Review: http://cr.openjdk.java.net/~anazarov/JDK-8178867/webrev.01 
<http://cr.openjdk.java.net/~anazarov/JDK-8178867/webrev.01>
JBS: https://bugs.openjdk.java.net/browse/JDK-8178867

—Thanks,
Andrei