Improve POC for CVE-2014-6277

I should have done this in the last PR.  Improve the POC for 6277.  The listed code did not work for me in a test environment.  This one is the exact version from lcamtuf's writeup at http://lcamtuf.blogspot.com/2014/10/bash-bug-how-we-finally-cracked.html

Tested in bash 4.3.11(1)