cli: add instruction for blkio-weight-device

[Ace-Tang]

blkio.weight_device need cfq io scheduler enable, add this
instruction for blkio-weight-device

add condition check for ci test TestRunBlockIOWeightDevice

Same problem also exist in #1346.

Signed-off-by: Ace-Tang aceapril@126.com

Ⅰ. Describe what this PR did

[root@r10d08216.sqa.zmf /root]
#pouch run -ti --blkio-weight-device "/dev/sda:1000" reg.docker.alibaba-inc.com/sunyuan/ubuntu:14.04 bash
Error: failed to run container 143a0e: {"message":"failed to create task, container id: 143a0e09b0d0d3905a6c56f66aa55576c0801fd50d1dc5072d6578eefc182231: OCI runtime create failed: container_linux.go:265: starting container process caused \"process_linux.go:348: container init caused \\\"process_linux.go:320: setting cgroup config for procHooks process caused \\\\\\\"failed to write 8:0 1000 to blkio.weight_device: write /sys/fs/cgroup/blkio/default/143a0e09b0d0d3905a6c56f66aa55576c0801fd50d1dc5072d6578eefc182231/blkio.weight_device: operation not supported\\\\\\\"\\\"\": unknown"}

Container fails to start, because sda's io scheduler is deadline, but blkio.weight_device need cfq,

[root@r10d08216.sqa.zmf /sys/fs/cgroup/blkio]
#cat /sys/block/sda/queue/scheduler 
noop [deadline] cfq 

Ⅱ. Does this pull request fix one issue?

Ⅲ. Describe how you did it

Ⅳ. Describe how to verify it

Ⅴ. Special notes for reviews

[codecov-io]

Codecov Report

Merging #1381 into master will decrease coverage by 0.07%.
The diff coverage is 0%.

@@            Coverage Diff             @@
##           master    #1381      +/-   ##
==========================================
- Coverage   38.61%   38.53%   -0.08%     
==========================================
  Files         248      248              
  Lines       16512    16512              
==========================================
- Hits         6376     6363      -13     
- Misses       9318     9328      +10     
- Partials      818      821       +3

Impacted Files	Coverage Δ
cli/common_flags.go	0% <0%> (ø)	⬆️
ctrd/container.go	48.06% <0%> (-2.33%)	⬇️
daemon/mgr/spec_linux.go	66.66% <0%> (-1.81%)	⬇️
daemon/mgr/network.go	68.3% <0%> (-0.5%)	⬇️
daemon/mgr/container.go	49.35% <0%> (-0.09%)	⬇️
daemon/logger/jsonfile/utils.go	71.66% <0%> (+1.66%)	⬆️

[Letty5411]

LGTM

[sunyuan3]

between 10 and 1000
Minimum should be 10

[Ace-Tang]

Yes, Could you help fix this, @sunyuan3