RFR(S): 8156521: Minor Fixes and cleanups in NetworkInterface.c

[Langer, Christoph]

Hi all,

can I please get a review for a change to NetworkInterface.c

bugreport: https://bugs.openjdk.java.net/browse/JDK-8156521
webrev: http://cr.openjdk.java.net/~clanger/webrevs/8156521.0/

Apart from quite a few whitespace changes to clean up the coding, I went through and replaced all occurences of strcpy with strncpy as this was a finding of a code scanner that we used. Also in function "enumIPv6Interfaces" for Linux the local variable plen was changed from int to short.

I ran builds on Linux, AIX, Solaris Sparc and Darwin to make sure nothing broke.

Thanks in advance
Christoph