RFR [8022584] Memory leak in some NetworkInterface methods

[Ivan Gerasimov]

Hello everybody!

Some methods of NetworkInterface class were reported to leak memory.
http://bugs.sun.com/view_bug.do?bug_id=JDK-8022584 (not yet available.)
Examples are isUp() and isLoopback().

Affected versions of jdk are 6, 7 and 8

Would you please review a simple fix that removes the unnecessary 
allocation?
http://cr.openjdk.java.net/~igerasim/8022584/0/webrev/

Sincerely yours,
Ivan