irqchip: Bulk conversion to generic_handle_domain_irq()

Wherever possible, replace constructs that match either
generic_handle_irq(irq_find_mapping()) or
generic_handle_irq(irq_linear_revmap()) to a single call to
generic_handle_domain_irq().

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
index 97d4d04..cf74cfa 100644
--- a/drivers/irqchip/irq-sifive-plic.c
+++ b/drivers/irqchip/irq-sifive-plic.c
@@ -233,13 +233,11 @@ static void plic_handle_irq(struct irq_desc *desc)
 	chained_irq_enter(chip, desc);
 
 	while ((hwirq = readl(claim))) {
-		int irq = irq_find_mapping(handler->priv->irqdomain, hwirq);
-
-		if (unlikely(irq <= 0))
+		int err = generic_handle_domain_irq(handler->priv->irqdomain,
+						    hwirq);
+		if (unlikely(err))
 			pr_warn_ratelimited("can't find mapping for hwirq %lu\n",
 					hwirq);
-		else
-			generic_handle_irq(irq);
 	}
 
 	chained_irq_exit(chip, desc);