Bug 966876 - Fix AVC denial in jbossas7 and jbosseap6 carts on startup

https://bugzilla.redhat.com/show_bug.cgi?id=966876

Redirect stderr to /dev/null when running oo-cgroup-read from bin/standalone.conf in jbosseap and jbossas v2 carts.  These are run with stderr redirected to a logfile in the gears tmp directory and oo-cgroup-read is trying to open a file handle to this logfile causing an AVC denial