jsondoclint: apply considerable clippy suggestions

Signed-off-by: onur-ozkan <work@onurozkan.dev>

Author: onur-ozkan

src/tools/jsondoclint/src/validator.rs

@@ -418,15 +418,13 @@ impl<'a> Validator<'a> {
             } else {
                 self.fail_expecting(id, expected);
             }
-        } else {
-            if !self.missing_ids.contains(id) {
-                self.missing_ids.insert(id);
+        } else if !self.missing_ids.contains(id) {
+            self.missing_ids.insert(id);
 
-                let sels = json_find::find_selector(&self.krate_json, &Value::String(id.0.clone()));
-                assert_ne!(sels.len(), 0);
+            let sels = json_find::find_selector(&self.krate_json, &Value::String(id.0.clone()));
+            assert_ne!(sels.len(), 0);
 
-                self.fail(id, ErrorKind::NotFound(sels))
-            }
+            self.fail(id, ErrorKind::NotFound(sels))
         }
     }