irqchip/loongson-pch-msi: Remove unneeded variable

irq_domain_alloc_irqs_parent() returns 0 on success and non-zero value
on failure, it is redudant to check its non-zero return value and then
return it, so just remove the variable "ret" and return directly in the
function pch_msi_parent_domain_alloc().
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1594087972-21715-7-git-send-email-yangtiezhu@loongson.cn

drivers/irqchip/irq-loongson-pch-msi.c

@@ -100,17 +100,12 @@ static int pch_msi_parent_domain_alloc(struct irq_domain *domain,
 					unsigned int virq, int hwirq)
 {
 	struct irq_fwspec fwspec;
-	int ret;
 
 	fwspec.fwnode = domain->parent->fwnode;
 	fwspec.param_count = 1;
 	fwspec.param[0] = hwirq;
 
-	ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
-	if (ret)
-		return ret;
-
-	return 0;
+	return irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
 }
 
 static int pch_msi_middle_domain_alloc(struct irq_domain *domain,