fill in x and y only if axes are valid

[tophyr]

Pull Request Type

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

Description

SDL identifies Android's keyboard as a D-Pad, and thus a "joystick", even though it has no available axis inputs. Checking all axes for validity, instead of just Z onward, enables this to work fine.

Related Issues

Checklist

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

[Lgt2x]

Looks fine, thanks!