Fix a typo in a comment.

Author: sunfishcode

library/std/src/sys/unix/fs.rs

@@ -1068,7 +1068,7 @@ pub fn link(src: &Path, dst: &Path) -> io::Result<()> {
     let src = cstr(src)?;
     let dst = cstr(dst)?;
     // Use `linkat` with `AT_FDCWD` instead of `link` as `link` leaves it
-    // implmentation-defined whether it follows symlinks. Pass 0 as the
+    // implementation-defined whether it follows symlinks. Pass 0 as the
     // `linkat` flags argument so that we don't follow symlinks.
     cvt(unsafe { libc::linkat(libc::AT_FDCWD, src.as_ptr(), libc::AT_FDCWD, dst.as_ptr(), 0) })?;
     Ok(())