ocfs2: trusted xattr missing CAP_SYS_ADMIN check

ocfs2: trusted xattr missing CAP_SYS_ADMIN check

The trusted extended attributes are only visible to the process which hvae
CAP_SYS_ADMIN capability but the check is missing in ocfs2 xattr_handler
trusted list.  The check is important because this will be used for
implementing mechanisms in the userspace for which other ordinary
processes should not have access to.

Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Taesoo kim <taesoo@gatech.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>