bugfix: can't quota on disk quota

[rudyfly]

Ⅰ. Describe what this PR did

Can't quota on diskquota when mount file system without diskquota.

Ⅱ. Does this pull request fix one issue?

Ⅲ. Why don't you add test cases (unit test/integration test)? (你真的觉得不需要加测试吗？)

Sorry, it's hard to add integration test, you can test it as below.

Ⅳ. Describe how to verify it

1. we just test prjquota on ubuntu 17.10

2. set your graph directory mount without prjquota/grpquota.

mount /dev/sdb /data

3. start pouchd and config graph directory in /etc/pouch/config.json

{
    "home-dir": "/data/pouch"
}

4. run container with disk quota is 5g

pouch run --rm --disk-quota 5g --name test -ti registry.hub.docker.com/library/fedora:latest df -h

Ⅴ. Special notes for reviews

Signed-off-by: Rudy Zhang rudyflyzhang@gmail.com

[codecov-io]

Codecov Report

Merging #2133 into master will increase coverage by 5.21%.
The diff coverage is 50%.

@@            Coverage Diff             @@
##           master    #2133      +/-   ##
==========================================
+ Coverage   59.63%   64.84%   +5.21%     
==========================================
  Files         208      208              
  Lines       16482    16490       +8     
==========================================
+ Hits         9829    10693     +864     
+ Misses       5453     4472     -981     
- Partials     1200     1325     +125

Flag	Coverage Δ
#criv1alpha1test	33.18% <50%> (+0.05%)	⬆️
#criv1alpha2test	33.83% <50%> (?)
#integrationtest	39.52% <50%> (+0.01%)	⬆️
#unittest	23.89% <0%> (-0.02%)	⬇️

Impacted Files	Coverage Δ
storage/quota/grpquota.go	0% <0%> (ø)	⬆️
storage/quota/prjquota.go	10.71% <100%> (+2.17%)	⬆️
daemon/mgr/container.go	56.07% <0%> (+0.2%)	⬆️
cri/v1alpha1/cri.go	64.13% <0%> (+0.34%)	⬆️
daemon/mgr/container_storage.go	48.41% <0%> (+0.97%)	⬆️
apis/server/utils.go	66.66% <0%> (+4.76%)	⬆️
cri/stream/httpstream/spdy/upgrade.go	60% <0%> (+5.71%)	⬆️
cri/stream/runtime.go	68.23% <0%> (+5.88%)	⬆️
cri/stream/remotecommand/httpstream.go	44.04% <0%> (+9.32%)	⬆️
cri/criservice.go	64.7% <0%> (+24.99%)	⬆️
... and 7 more

[HusterWan]

lgtm