audit: cull redundancy in audit_rule_change

Re-factor audit_rule_change() to reduce the amount of code redundancy and
simplify the logic.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

kernel/auditfilter.c

@@ -1064,31 +1064,27 @@ int audit_rule_change(int type, __u32 portid, int seq, void *data,
 	int err = 0;
 	struct audit_entry *entry;
 
+	entry = audit_data_to_entry(data, datasz);
+	if (IS_ERR(entry))
+		return PTR_ERR(entry);
+
 	switch (type) {
 	case AUDIT_ADD_RULE:
-		entry = audit_data_to_entry(data, datasz);
-		if (IS_ERR(entry))
-			return PTR_ERR(entry);
-
 		err = audit_add_rule(entry);
 		audit_log_rule_change("add_rule", &entry->rule, !err);
-		if (err)
-			audit_free_rule(entry);
 		break;
 	case AUDIT_DEL_RULE:
-		entry = audit_data_to_entry(data, datasz);
-		if (IS_ERR(entry))
-			return PTR_ERR(entry);
-
 		err = audit_del_rule(entry);
 		audit_log_rule_change("remove_rule", &entry->rule, !err);
-		audit_free_rule(entry);
 		break;
 	default:
 		err = -EINVAL;
 		WARN_ON(1);
 	}
 
+	if (err || type == AUDIT_DEL_RULE)
+		audit_free_rule(entry);
+
 	return err;
 }