Fix failed test

Author: zxvfc

tests/integration.rs

@@ -84,13 +84,13 @@ mod common {
         let mut cmd = cargo_bin_cmd!("diffutils");
         cmd.arg("diff");
         cmd.arg(&nopath).arg(&nopath);
-        cmd.assert().code(predicate::eq(2)).failure().stderr(
-            predicate::str::contains(format!(
+        cmd.assert()
+            .code(predicate::eq(2))
+            .failure()
+            .stderr(predicate::str::contains(format!(
                 ": {}: {error_message}\n",
                 &nopath.as_os_str().to_string_lossy()
-            ))
-            .count(2),
-        );
+            )));
 
         Ok(())
     }