irqchip: renesas-irqc: Fix irqc_probe error handling

The code in goto err3 path is wrong because it will call fee_irq() with k == 0,
which means it does free_irq(p->irq[-1].requested_irq, &p->irq[-1]);

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/drivers/irqchip/irq-renesas-irqc.c b/drivers/irqchip/irq-renesas-irqc.c
index 927bff3..2f404ba 100644
--- a/drivers/irqchip/irq-renesas-irqc.c
+++ b/drivers/irqchip/irq-renesas-irqc.c
@@ -248,8 +248,8 @@
 
 	return 0;
 err3:
-	for (; k >= 0; k--)
-		free_irq(p->irq[k - 1].requested_irq, &p->irq[k - 1]);
+	while (--k >= 0)
+		free_irq(p->irq[k].requested_irq, &p->irq[k]);
 
 	irq_domain_remove(p->irq_domain);
 err2: