Update for staticcheck compliance

[geofffranks]

👋Howdy!

We (the App Platform Runtime WG) pull credhub-cli into the diego-release codebase, and are trying to run staticcheck on all of its codebases. We found a few things flagged on credhub-cli, and would love it if y'all could incorporate these changes so we don't have to jump through hoops to whitelist certain codebases from our staticcheck automation.

[peterhaochen47]

Hi, thank you! We'll take a look!

But meanwhile, there are 2 test failures from running make all on this branch:

[1709773266] CredHub API Client Suite - 182/182 specs - 15 procs •••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••
------------------------------
• [FAILED] [0.001 seconds]
Client() When a SOCKS5Proxy is set in the environment [It] returns an http.Client with a Dial function
/Users/peterch/workspace/tmp/credhub-cli/credhub/client_test.go:26

  [FAILED] Expected
      <func(context.Context, string, string) (net.Conn, error)>: nil
  not to be nil
  In [It] at: /Users/peterch/workspace/tmp/credhub-cli/credhub/client_test.go:33 @ 03/06/24 17:01:24.452
------------------------------
•••••••••••••••••••••••
------------------------------
• [FAILED] [0.002 seconds]
Client() With Dial [It] should return a http.Client with a dial function
/Users/peterch/workspace/tmp/credhub-cli/credhub/client_test.go:140

  [FAILED] Expected
      <func(context.Context, string, string) (net.Conn, error)>: nil
  not to be nil
  In [It] at: /Users/peterch/workspace/tmp/credhub-cli/credhub/client_test.go:146 @ 03/06/24 17:01:24.457
------------------------------
••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••

Summarizing 2 Failures:
  [FAIL] Client() With Dial [It] should return a http.Client with a dial function
  /Users/peterch/workspace/tmp/credhub-cli/credhub/client_test.go:146
  [FAIL] Client() When a SOCKS5Proxy is set in the environment [It] returns an http.Client with a Dial function
  /Users/peterch/workspace/tmp/credhub-cli/credhub/client_test.go:33

Ran 182 of 182 Specs in 0.064 seconds
FAIL! -- 180 Passed | 2 Failed | 0 Pending | 0 Skipped

[Tallicia]

Hi @geofffranks Any update on these failures?

[geofffranks]

oh, thanks! i missed this comment. Will take a look today.

[geofffranks]

Ok, should pass tests now @Tallicia @peterhaochen47 - thanks!

[Tallicia]

All tests passed on local confirmation. Planning for merge.

[Tallicia]

Updates for staticCheck look ok