avr32/irq: Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc

Use irq_desc_get_xxx() to avoid redundant lookup of irq_desc while we
already have a pointer to corresponding irq_desc.
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Acked-by: Hans-Christian Egtvedt <egtvedt@samfundet.no>
Cc: Haavard Skinnemoen <hskinnemoen@gmail.com>
Link: http://lkml.kernel.org/r/20150713100606.527106283@linutronix.deSigned-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/avr32/mach-at32ap/pio.c

@@ -286,7 +286,7 @@ static void gpio_irq_handler(unsigned irq, struct irq_desc *desc)
 	struct pio_device	*pio = irq_desc_get_chip_data(desc);
 	unsigned		gpio_irq;
 
-	gpio_irq = (unsigned) irq_get_handler_data(irq);
+	gpio_irq = (unsigned) irq_desc_get_handler_data(desc);
 	for (;;) {
 		u32		isr;