Codereview request: 8026028 [findbugs] findbugs report some issue in com.sun.jmx.snmp package

[shanliang]

Hi,

Please review the following fix, main issue here is that we should clone 
an internal variable before returning.

webrev:
http://cr.openjdk.java.net/~sjiang/JDK-8026028/00/

bug
https://bugs.openjdk.java.net/browse/JDK-8026028

Thanks,
Shanliang