RFR JDK-8210394: (zipfs) jdk/nio/zipfs/ZFSTests.java rootdir.zip: The process cannot access the file because it is being used by another process

[Xueming Shen]

Hi

Please help review the change for JDK-8210394.

issue: https://bugs.openjdk.java.net/browse/JDK-8210394
webrev: http://cr.openjdk.java.net/~sherman/8210394/webrev

It appears the "zipfile" for testing is opened with "new 
ZipFile(...).stream()..." without
explicit close might be the direct trigger of the failure. (a mach5 job 
with the proposed
fix seems to pass without this failure)

Thanks,
Sherman