KVM: lib: use jump label to handle resource release in irq_bypass_register_consumer()

Use out_err jump label to handle resource release. It's a
good practice to release resource in one place and help
eliminate some duplicated code.
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

virt/lib/irqbypass.c

@@ -179,6 +179,7 @@ int irq_bypass_register_consumer(struct irq_bypass_consumer *consumer)
 {
 	struct irq_bypass_consumer *tmp;
 	struct irq_bypass_producer *producer;
+	int ret;
 
 	if (!consumer->token ||
 	    !consumer->add_producer || !consumer->del_producer)
@@ -193,20 +194,16 @@ int irq_bypass_register_consumer(struct irq_bypass_consumer *consumer)
 
 	list_for_each_entry(tmp, &consumers, node) {
 		if (tmp->token == consumer->token || tmp == consumer) {
-			mutex_unlock(&lock);
-			module_put(THIS_MODULE);
-			return -EBUSY;
+			ret = -EBUSY;
+			goto out_err;
 		}
 	}
 
 	list_for_each_entry(producer, &producers, node) {
 		if (producer->token == consumer->token) {
-			int ret = __connect(producer, consumer);
-			if (ret) {
-				mutex_unlock(&lock);
-				module_put(THIS_MODULE);
-				return ret;
-			}
+			ret = __connect(producer, consumer);
+			if (ret)
+				goto out_err;
 			break;
 		}
 	}
@@ -216,6 +213,10 @@ int irq_bypass_register_consumer(struct irq_bypass_consumer *consumer)
 	mutex_unlock(&lock);
 
 	return 0;
+out_err:
+	mutex_unlock(&lock);
+	module_put(THIS_MODULE);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(irq_bypass_register_consumer);