Added disk usage and failed SSH login checks

[cuddiecoder]

This pull request enhances the LinEnum script by adding additional system enumeration checks to improve visibility of potential security and resource-related issues.

Changes Made
Added disk usage enumeration to help identify full or nearly full filesystems
Added checks for failed SSH login attempts to assist in detecting potential brute-force activity or unauthorized access attempts
Integrated both checks into existing output flow without modifying core script logic
Notes
No existing functionality has been removed or altered
Enhancements are additive and non-breaking
Focus is on improving system visibility during enumeration
Testing

Tested locally on Kali Linux to ensure:

Script executes without errors
New checks display expected output
No impact on existing enumeration sections

[cuddiecoder]

The changes are complete and ready for review. The additions for disk usage and failed SSH login checks have been implemented and tested locally. No conflicts with the base branch, and the changes can be cleanly merged.