LU-1438 quota: quota active checking is missed on slave

LU-1438 quota: quota active checking is missed on slave

On quota slave, we missed checking if quota is enabled in the
quota_check_common() and several other places. Which could cause
slave retry acquire quota in quota_chk_acq_common() infinitely
when the quota is already turned off on master.

Signed-off-by: Niu Yawei <niu@whamcloud.com>
Change-Id: Iaa48c7cca05daf595b6d3b7e4025c7650e460918
Reviewed-on: http://review.whamcloud.com/3097
Tested-by: Hudson
Reviewed-by: Fan Yong <yong.fan@whamcloud.com>
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Johann Lombardi <johann@whamcloud.com>