LU-709 build: LC_XATTR_ACL & LC_POSIX_ACL_XATTR_H cleanup

LU-709 build: LC_XATTR_ACL & LC_POSIX_ACL_XATTR_H cleanup

xattr_acl.h removed since 2.6.13 and posix_acl_xattr.h
exist since 2.6.11. So just use posix_acl_xattr.h for now.
And removed relate codes.

Change-Id: Ibefd4db87fa79ec9ee6365d48c83abd0dda0e063
Signed-off-by: yangsheng <ys@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/1916
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Fan Yong <yong.fan@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>