rust: kbuild: run Clippy for `rusttest` code

Running Clippy for `rusttest` code is useful to catch issues there too,
even if the code is not as critical. In the future, this code may also
run in kernelspace and could be copy-pasted. Thus it is useful to keep
it under the same standards. For instance, it will now make us add
`// SAFETY` comments.

It also makes everything more consistent.

Thus clean the few issues spotted by Clippy and start running it.

Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

0 files changed, 0 insertions, 0 deletions