When RT_USING_DEBUG is disabled, variables used only in RT_ASSERT
statements become unused, triggering -Wunused-but-set-variable compiler
warnings. These variables are essential for runtime assertions in debug
builds but appear unused in release builds.
Example:
- Variables used in RT_ASSERT(var != RT_NULL) checks
- Affects multiple drivers and components using RT_ASSERT
This is a general cleanup to improve code compilation without affecting
functionality.