tsort: replace nix by rustix

src/uu/tsort/Cargo.toml

@@ -28,7 +28,7 @@ uucore = { workspace = true }
 rustc-hash = { workspace = true }
 
 [target.'cfg(unix)'.dependencies]
-nix = { workspace = true, features = ["fs"] }
+rustix = { workspace = true, features = ["fs"] }
 
 [[bin]]
 name = "tsort"

src/uu/tsort/src/tsort.rs

@@ -87,14 +87,14 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
                 target_os = "freebsd",
             ))]
             {
-                use nix::fcntl::{PosixFadviseAdvice, posix_fadvise};
+                use rustix::fs::{Advice, fadvise};
                 use std::os::unix::io::AsFd;
 
-                posix_fadvise(
+                fadvise(
                     file.as_fd(),
-                    0, // offset 0 => from the start of the file
-                    0, // length 0 => for the whole file
-                    PosixFadviseAdvice::POSIX_FADV_SEQUENTIAL,
+                    0,    // offset 0 => from the start of the file
+                    None, // None => for the whole file
+                    Advice::Sequential,
                 )
                 .ok();
             }