testsuite: remove *lstat* wrappers

testsuite: remove *lstat* wrappers

The majority of these were initially introduced with commit 123e827
("testsuite preload: Factorize into macros, add more stat and open
variants").

The commit itself was meant to refactor existing wrappers and add new
_xstat (aka stat) variants. The lstat variants were never used in kmod
directly nor indirectly via header macros.

The rest were added to mimic the original, without much testing it
seems.

They are all dead code - remove them.

In theory one could have a macro/helper that calls `lstat` for `stat`
itself, although that isn't a practical solution for a few reasons.

The functionality across the two varies, where if the path provided is
a symlink `stat` follows it, while `lstat` gets the details for the link
itself. To fix this, the wrapper would need second syscall to resolve
the symlink, which will cause notable performance regression wrt using
using the `stat`/`stat64` syscall alone.

Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/131
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>