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>