[7u6] request for approval : 7149608: Default TZ detection fails on linux when symbolic links to non default location used.

[Seán Coffey]

Nearly forgot to port this to 7u6. Fix has been in jdk 8 for a few 
months now.

Identical code change.
jdk 8 changeset : http://hg.openjdk.java.net/jdk8/tl/jdk/rev/6bbafa8404eb
bug report : http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7149608
Regards,
Sean.