patch 9.1.1628: fuzzy.c has a few issues

patch 9.1.1628: fuzzy.c has a few issues

Problem:  fuzzy.c has a few issues
Solution: Use Vims memory management, update style
          (glepnir)

Problem:
- Missing cleanup of lmatchpos lists causing memory leaks
- Missing error handling for list operations
- Use of malloc() instead of Vim's alloc() functions
- Inconsistent C-style comments
- Missing null pointer checks for memory allocation
- Incorrect use of vim_free() for list objects

Solution:
- Add proper cleanup of lmatchpos in done section using list_free()
- Set lmatchpos to NULL after successful transfer to avoid confusion
- Add error handling for list_append_tv() failures
- Replace malloc() with alloc() and add null pointer checks
- Convert C-style comments to C++ style for consistency
- Fix vim_free() calls to use list_free() for list objects

closes: #17984

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>