irqchip/irq-pic32-evic: Fix bug with external interrupts.

The wrong external interrupt bits are being set, offset by 1.

Signed-off-by: Joshua Henderson <[e-mail]>
Signed-off-by: Purna Chandra Mandal <[e-mail]>
Signed-off-by: Marc Zyngier <[e-mail]>

drivers/irqchip/irq-pic32-evic.c

···
 	/* set polarity for external interrupts only */
 	for (i = 0; i < ARRAY_SIZE(priv->ext_irqs); i++) {
 		if (priv->ext_irqs[i] == data->hwirq) {
-			ret = pic32_set_ext_polarity(i + 1, flow_type);
+			ret = pic32_set_ext_polarity(i, flow_type);
 			if (ret)
 				return ret;
 		}