MSFT_xUserResource.psm1: Fix script analyzer issues

[mhendric]

Pull Request (PR) description

Fixes remaining script analyzer issues in MSFT_xUserResource.psm1.

This Pull Request (PR) fixes the following issues

• Fixes MSFT_xUserResource.psm1: Fix Custom DSC Resource Kit PSSA rule violations #492

Task list

• Added an entry under the Unreleased section of the change log in
  CHANGELOG.md. Entry should say what was changed, and how that affects
  users (if applicable).
• Resource documentation added/updated in README.md.
• Resource parameter descriptions added/updated in README.md, schema.mof
  and comment-based help.
• Comment-based help added/updated.
• Localization strings added/updated in all localization files as
  appropriate.
• Examples appropriately added/updated.
• Unit tests added/updated. See
  DSC Resource Testing Guidelines.
• Integration tests added/updated (where possible). See
  DSC Resource Testing Guidelines.
• New/changed code adheres to
  DSC Resource Style Guidelines and Best Practices

---

This change is 

[codecov-io]

Codecov Report

Merging #553 into dev will not change coverage.
The diff coverage is 50%.

@@         Coverage Diff         @@
##            dev   #553   +/-   ##
===================================
  Coverage    74%    74%           
===================================
  Files        27     27           
  Lines      4029   4029           
  Branches      4      4           
===================================
  Hits       3009   3009           
  Misses     1016   1016           
  Partials      4      4

[PlagueHO]

Will review once the conflicts are fixed.

[PlagueHO]

Reviewed 2 of 2 files at r1.
Reviewable status: complete! all files reviewed, all discussions resolved

[PlagueHO]

Just waiting for the CI to finish before merging.