ln -i: adjust the behavior to match the GNU change

Just like mv & cp

Matches the change upstream
7a69df88999bedd8e9fccf9f3dfa9ac6907fab66

src/uu/ln/src/ln.rs

@@ -392,7 +392,7 @@ fn link(src: &Path, dst: &Path, settings: &Settings) -> UResult<()> {
             OverwriteMode::NoClobber => {}
             OverwriteMode::Interactive => {
                 if !prompt_yes!("overwrite {}?", dst.quote()) {
-                    return Ok(());
+                    return Err(LnError::SomeLinksFailed.into());
                 }
 
                 if fs::remove_file(dst).is_ok() {};

tests/by-util/test_ln.rs

@@ -116,7 +116,7 @@ fn test_symlink_interactive() {
         .ucmd()
         .args(&["-i", "-s", file, link])
         .pipe_in("n")
-        .succeeds()
+        .fails()
         .no_stdout();
 
     assert!(at.file_exists(file));