ceph: remove useless ACL check

posix_acl_xattr_set() already does the check, and it's the only
way to feed in an ACL from userspace.
So the check here is useless, remove it.

Signed-off-by: zhang zhen <zhenzhang.zhang@huawei.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>