fmt: fix clippy warnings on all targets

Drop an unused test fixture constant, move download_trust_ppa_key above
the test module that precedes it, and simplify two test borrows.

src/apt/keyring.rs

@@ -198,37 +198,6 @@ fn validate_keyring_dir(dir_uid: u32, mode: u32, euid: u32) -> Result<(), String
     Ok(())
 }
 
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_validate_keyring_dir_accepts_private_dir_owned_by_current_user() {
-        assert!(validate_keyring_dir(1000, 0o700, 1000).is_ok());
-        assert!(validate_keyring_dir(1000, 0o750, 1000).is_ok());
-        assert!(validate_keyring_dir(1000, 0o1744, 1000).is_ok());
-        assert!(validate_keyring_dir(0, 0o700, 0).is_ok());
-    }
-
-    #[test]
-    fn test_validate_keyring_dir_rejects_foreign_owner() {
-        let err = validate_keyring_dir(1000, 0o700, 1001).unwrap_err();
-        assert!(err.contains("owned by uid 1000"));
-        let err = validate_keyring_dir(1001, 0o700, 1000).unwrap_err();
-        assert!(err.contains("owned by uid 1001"));
-    }
-
-    #[test]
-    fn test_validate_keyring_dir_rejects_group_or_other_writable() {
-        assert!(validate_keyring_dir(1000, 0o770, 1000).is_err());
-        assert!(validate_keyring_dir(1000, 0o706, 1000).is_err());
-        assert!(validate_keyring_dir(1000, 0o707, 1000).is_err());
-        assert!(validate_keyring_dir(1000, 0o777, 1000).is_err());
-        // Sticky bit does not neutralize the group/other write bits.
-        assert!(validate_keyring_dir(1000, 0o1777, 1000).is_err());
-    }
-}
-
 /// Download and import a PPA key using Launchpad API
 ///
 /// # Arguments
@@ -332,3 +301,34 @@ pub async fn download_trust_ppa_key(
     );
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_validate_keyring_dir_accepts_private_dir_owned_by_current_user() {
+        assert!(validate_keyring_dir(1000, 0o700, 1000).is_ok());
+        assert!(validate_keyring_dir(1000, 0o750, 1000).is_ok());
+        assert!(validate_keyring_dir(1000, 0o1744, 1000).is_ok());
+        assert!(validate_keyring_dir(0, 0o700, 0).is_ok());
+    }
+
+    #[test]
+    fn test_validate_keyring_dir_rejects_foreign_owner() {
+        let err = validate_keyring_dir(1000, 0o700, 1001).unwrap_err();
+        assert!(err.contains("owned by uid 1000"));
+        let err = validate_keyring_dir(1001, 0o700, 1000).unwrap_err();
+        assert!(err.contains("owned by uid 1001"));
+    }
+
+    #[test]
+    fn test_validate_keyring_dir_rejects_group_or_other_writable() {
+        assert!(validate_keyring_dir(1000, 0o770, 1000).is_err());
+        assert!(validate_keyring_dir(1000, 0o706, 1000).is_err());
+        assert!(validate_keyring_dir(1000, 0o707, 1000).is_err());
+        assert!(validate_keyring_dir(1000, 0o777, 1000).is_err());
+        // Sticky bit does not neutralize the group/other write bits.
+        assert!(validate_keyring_dir(1000, 0o1777, 1000).is_err());
+    }
+}