The implementation of opendir() in lib/roken/dirent.c takes as input a
directory name. For the contents of the specified directory to be
enumerated correctly, this directory name must be converted to a
wildcard.
Appease the compiler by resolving some of the reported warnings,
including:
- Control paths that don't return.
- Potentially uninitialized variables.
- Unused local variables.
- Unreachable code.
- Type safety.
- Synchronize declarations with definitions for functions.
