bugfix: don't set mount tab when rootfs diskquota is null

[rudyfly]

Ⅰ. Describe what this PR did

Fixes: When rootfs diskquota is null, it will not set mount tab

Ⅱ. Does this pull request fix one issue?

NONE

Ⅲ. Describe how you did it

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

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

[codecov-io]

Codecov Report

Merging #1926 into master will increase coverage by 0.4%.
The diff coverage is 28.57%.

@@           Coverage Diff            @@
##           master   #1926     +/-   ##
========================================
+ Coverage    62.8%   63.2%   +0.4%     
========================================
  Files         200     200             
  Lines       15567   15571      +4     
========================================
+ Hits         9777    9842     +65     
+ Misses       4544    4483     -61     
  Partials     1246    1246

Flag	Coverage Δ
#criv1alpha1test	33.67% <28.57%> (+0.39%)	⬆️
#criv1alpha2test	34.19% <28.57%> (+0.46%)	⬆️
#integrationtest	38.29% <28.57%> (+0.36%)	⬆️
#unittest	20.7% <0%> (-0.01%)	⬇️

Impacted Files	Coverage Δ
daemon/mgr/spec_hook.go	44.79% <28.57%> (+31.74%)	⬆️
ctrd/image.go	79.2% <0%> (-1.99%)	⬇️
cri/v1alpha1/cri.go	65.4% <0%> (+0.18%)	⬆️
cri/v1alpha2/cri.go	66.49% <0%> (+0.52%)	⬆️
cri/v1alpha2/cri_wrapper.go	55.17% <0%> (+1.29%)	⬆️
cri/v1alpha1/cri_wrapper.go	57.14% <0%> (+1.33%)	⬆️
ctrd/container.go	52.23% <0%> (+2.06%)	⬆️
storage/quota/quota.go	19.81% <0%> (+7.2%)	⬆️
storage/quota/prjquota.go	8.09% <0%> (+8.09%)	⬆️

[CodeJuan]

LGTM