Minor improvements to `cf_OpenLibrary()`’s HOG2 id detection code

[Jayman2000]

Pull Request Type

• [ ] GitHub Workflow changes
• [ ] Documentation or Wiki changes
• [ ] Build and Dependency changes
• [x] Runtime changes
  • [ ] Render changes
  • [ ] Audio changes
  • [ ] Input changes
  • [ ] Network changes
  • [x] Other changes

Description

This PR contains two minor improvements to the code that detects whether or not .hog files actually begin with the ASCII characters HOG2. See the commit messages for details.

Related Issues

Screenshots (if applicable)

Checklist

• [x] I have tested my changes locally and verified that they work as intended.
• [ ] I have documented any new or modified functionality.
• [x] I have reviewed the changes to ensure they do not introduce any unnecessary complexity or duplicate code.
• [x] I understand that by submitting this pull request, I am agreeing to license my contributions under the project's license.

Additional Comments

[GravisZro]

It would be better to simply replace #define HOG_TAG_STR "HOG2" with a std::string_view. However, my understanding is that @winterheart plans on replacing cfile.* and hogfile.* entirely which would negate any work on them.

[winterheart]

OK, ready to merge, thank you!