RFR 8154543, NetworkInterfaceStreamTest.java fails intermittently after JDK-8146758

[Felix Yang]

Hi there,
     I introduced a problem in fix for JDK-8146758. When calling 
allNetworkInterfaces(), it will concat sub interfaces into the stream 
incorrectly. Then the test fails on a Solaris host which has 
virtual(sub) interfaces.

Bug: https://bugs.openjdk.java.net/browse/JDK-8154543
Webrev: http://cr.openjdk.java.net/~xiaofeya/8154543/webrev.00/

Thanks,
Felix