gpio: ljca: Fix duplicated IRQ mapping

The generic_handle_domain_irq() function resolves the hardware IRQ
internally. The driver performed a duplicative mapping by calling
irq_find_mapping() first, which could lead to an RCU stall.

Delete the redundant irq_find_mapping() call and pass the hardware IRQ
directly to generic_handle_domain_irq().

Fixes: c5a4b6f ("gpio: Add support for Intel LJCA USB GPIO driver")
Signed-off-by: Haotian Zhang <vulab@iscas.ac.cn>
Link: https://lore.kernel.org/r/20251023070231.1305-1-vulab@iscas.ac.cn
[Bartosz: remove unused variable]
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

Author: ISCAS-Vulab

drivers/gpio/gpio-ljca.c

@@ -286,22 +286,14 @@ static void ljca_gpio_event_cb(void *context, u8 cmd, const void *evt_data,
 {
 	const struct ljca_gpio_packet *packet = evt_data;
 	struct ljca_gpio_dev *ljca_gpio = context;
-	int i, irq;
+	int i;
 
 	if (cmd != LJCA_GPIO_INT_EVENT)
 		return;
 
 	for (i = 0; i < packet->num; i++) {
-		irq = irq_find_mapping(ljca_gpio->gc.irq.domain,
-				       packet->item[i].index);
-		if (!irq) {
-			dev_err(ljca_gpio->gc.parent,
-				"gpio_id %u does not mapped to IRQ yet\n",
-				packet->item[i].index);
-			return;
-		}
-
-		generic_handle_domain_irq(ljca_gpio->gc.irq.domain, irq);
+		generic_handle_domain_irq(ljca_gpio->gc.irq.domain,
+					packet->item[i].index);
 		set_bit(packet->item[i].index, ljca_gpio->reenable_irqs);
 	}