enhance: use bit operation to get device major/minor

[houstar]

Signed-off-by: Leno Hou lenohou@gmail.com

Ⅰ. Describe what this PR did

In computer architecture, bit operation use less CPU cycle than Div and Mod

Formula:
Val / 2^n   =  Val >> n                (right shift n bit)
Val % 2^n  = Val & (2^n -1)            (only get the low bit)

Ⅱ. Does this pull request fix one issue?

NO

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

NO

Ⅳ. Describe how to verify it

NO

Ⅴ. Special notes for reviews

[codecov]

Codecov Report

Merging #2567 into master will decrease coverage by 0.02%.
The diff coverage is 50%.

@@            Coverage Diff             @@
##           master    #2567      +/-   ##
==========================================
- Coverage   69.17%   69.15%   -0.03%     
==========================================
  Files         278      278              
  Lines       18623    18623              
==========================================
- Hits        12883    12879       -4     
- Misses       4268     4270       +2     
- Partials     1472     1474       +2

Flag	Coverage Δ
#criv1alpha1test	31.25% <0%> (-0.03%)	⬇️
#criv1alpha2test	35.63% <0%> (+0.14%)	⬆️
#integrationtest	40.66% <50%> (-0.02%)	⬇️
#nodee2etest	32.57% <0%> (-0.09%)	⬇️
#unittest	26.76% <0%> (ø)	⬆️

Impacted Files	Coverage Δ
daemon/mgr/spec_linux.go	76.74% <50%> (ø)	⬆️
cri/v1alpha1/cri.go	60.59% <0%> (-0.34%)	⬇️
daemon/mgr/container.go	58.79% <0%> (-0.22%)	⬇️

[houstar]

@Ace-Tang Could you help me to take a look this minor changes? Thanks.

[firjest]

LGTM

[allencloud]

Thanks a lot for your work. @houstar