rust: str: use the "kernel vertical" imports style

Status from this message: Applied series to `rust-next` since the second is a "fix" for nightly

Get series with b4

b4 am [email protected]

Versions newest first

#	Subject and files	Size	Replies	Applied
1/2	rust: str: use the "kernel vertical" imports style`rust/kernel/str.rs`	+19 -5	2 replies
2/2	rust: str: clean unused import for Rust >= 1.98`rust/kernel/str.rs`	+0 -1	2 replies

All 2 patches have a Reviewed-by or Acked-by.

Patch	Alice Ryhl	Gary Guo
1/2		R-b
2/2	R-b	R-b

Trailers given in replies are filled; those carried in the patches from earlier versions are outlined with dashes.