IRQ: Typedef the IRQ handler function type

Typedef the IRQ handler function type.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1356d1e5fd256997e3d3dce0777ab787d0515c7a commit)
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 92be519..6879202 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -427,8 +427,7 @@
  *	IRQF_SAMPLE_RANDOM	The interrupt can be used for entropy
  *
  */
-int request_irq(unsigned int irq,
-		irqreturn_t (*handler)(int, void *, struct pt_regs *),
+int request_irq(unsigned int irq, irq_handler_t handler,
 		unsigned long irqflags, const char *devname, void *dev_id)
 {
 	struct irqaction *action;
@@ -475,4 +474,3 @@
 	return retval;
 }
 EXPORT_SYMBOL(request_irq);
-