LU-4704 test: enable acl 974 and 2561 series test

LU-4704 test: enable acl 974 and 2561 series test

Add acl/{974,974_remote,2561,2561_zfs}.test to the
lustre/tests/Makefile.am nobase_noinst_DATA list, and fix acl/run
test to fail if the test scripts are missing.
acl/2561_zfs.test is a newly created test file for zfs. Since zfs
allocates a 512 byte dnode for empty file, its "ls -s" result is
different from ldiskfs'.

Signed-off-by: Emoly Liu <emoly.liu@intel.com>
Change-Id: I11be072eb1954fff3b7a19231b82345b3073a534
Reviewed-on: http://review.whamcloud.com/9541
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Jian Yu <jian.yu@intel.com>