cli/command: rename vars for consistency and prevent shadowing

[thaJeztah]

• relates to / needed for vendor: github.com/moby/moby/api, moby/moby/client master #6255

- Human readable description for the release notes

- A picture of a cute animal (not mandatory but encouraged)

[codecov-commenter]

Codecov Report

❌ Patch coverage is 77.95276% with 28 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
cli/command/swarm/ca.go	30.76%	8 Missing and 1 partial ⚠️
cli/command/service/inspect.go	0.00%	7 Missing ⚠️
cli/command/stack/swarm/ps.go	0.00%	5 Missing ⚠️
cli/command/network/list.go	66.66%	1 Missing and 1 partial ⚠️
cli/command/node/cmd.go	0.00%	2 Missing ⚠️
cli/command/node/inspect.go	85.71%	0 Missing and 1 partial ⚠️
cli/command/node/ps.go	85.71%	0 Missing and 1 partial ⚠️
cli/command/secret/inspect.go	83.33%	0 Missing and 1 partial ⚠️

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