LU-998 acl: declare acl operation for setattr

LU-998 acl: declare acl operation for setattr

Setattr on ATTR_MODE may set acl if acl is enabled, and it should be
declared in advance.

Signed-off-by: Lai Siyao <laisiyao@whamcloud.com>
Change-Id: Id9c94c5498f8fee0a79986bb424444f658c98e60
Reviewed-on: http://review.whamcloud.com/1984
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Li Wei <liwei@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>