Philip/random clean up fixes

[pamolloy]

PR Description

A few random fixes related to porting libiio to a MCU.

PR Type

• [X] Bug fix (a change that fixes an issue)
• [ ] New feature (a change that adds new functionality)
• [ ] Breaking change (a change that affects other repos or cause CIs to fail)

PR Checklist

• [x] I have conducted a self-review of my own code changes
• [ ] I have commented new code, particularly complex or unclear areas
• [x] I have checked that I did not introduce new warnings or errors (CI output)
• [x] I have checked that components that use libiio did not break
• [ ] I have updated the documentation accordingly (GitHub Pages, READMEs, etc)